Earlier this Summer, I celebrated my third year as a companion and reflected on the ways in which I've changed since entering this world.  

was look up the word demimonde in the dictionary. :p  So thanks for that bit of homework.  
 
I have definitely gotten to fulfill a ton of fantasies not possible with regular girls, and I've discovered that some of them are still better in fantasy and not in real life.  I've also learned that half the positions you see in pornos really don't feel that good for either partner.  
 
But for the more impactful effects, I have become more comfortable socially around women.  I think spending time with a helpful courtesan has helped me understand a little better what makes a woman tick.  I'm not saying I've become the "chick whisperer" or anything, only that I got a little better at interacting with them.  
 
I've also learned how to do things and cover my tracks better.  

dem·i·monde
(in 19th-century France) the class of women considered to be of doubtful morality and social standing.

I have definitely been changed by my interactions with providers over the years, but it is hard to condense it all down to a manageable number of sentences. It's like asking a fish about water.

And now I've learned my something new for today.  In response to your question:  I've come to realize that monogamy is not natural.    

(Started when I was 22.) that I have no idea who I would be had I never got involved.

....to ever notice a change.  

Young, handsome, successful bachelor (only the last descriptor still applies) up until the age of 32 when I married, I had no problem getting hot model types into my bed, but when I found myself suddenly a widower at age 48, I wanted to start seducing 20-somethings again, but soon discovered that even though I was doing some of my best selling, not many were buying, so enter the hobby.  The resulting change in my demeanor is that it makes me feel young again and makes my friends ask what's up with the perpetual shit-eating grin. These are indeed happy times for me.

Growing up on "that side of the tracks" I have been around hookers pretty much all my life and my "first time" with a hooker was at the ripe old age of 15, best five bucks I ever spent. lol  

...but I'm much happier for all the amazing experiences I've had. I'm still the irreverant, fun loving guy I've always been. It's just that now that my children are off the payroll, I not only have extra funds, but extra time to explore all the things I've wanted to.

Though not a widower my sentiments and spin on the thread exactly echo cspatz and cdl. I walk around with almost the confidence I had back in my 30`s. I`m much more patient and I smile a lot. I flirt all the time with barmaids, waitresses, all females in fact and you know what? They flirt back. Life is good again.

Still have kids at home that they're going to have two problems to deal with once they leave:

I am not a member of the “demi-monde.”  This is a part-time job, not my lifestyle.  

...but I think I'd like to monde your demi. 😎

...I'd say that they're opportunities. 😎

My taste for Latina providers prompted me to learn a new language (Spanish). I pursued this interest further with mongering trips to Latin America, which I enjoyed it other, non-sexual ways, such as appreciating nature.

Dumas, fils, certainement.

"I learned it in the demimonde," or better yet "Alors, je l'ai appris dans le demimonde" and impress her with your French!

I'm kind of an introverted, artistic-intellectual guy, and while I find that women appreciate those qualities later on, most of them don't in high school or college, at least not where I was.  So I came into early manhood with little experience and zero self-confidence about sex and relationships.

Emile Zola est la littérature.  Dumas est une bagatelle.

A lot has changed, but the biggie for me is the confidence in my own body, and the confidence enjoying pleasure from a man without feeling a lick of insecurity. Result: Many more Ohs. A part of that is the intellectual stimulation I get here. When I leave, I'll be looking for what I got here in men.

Demimonde is just one of those terms that I really dislike. One of your staffers should have briefed you.

Because I know when and where my sex is coming from, I now am able to talk to any woman that I wasn't able to before.  
With that dance off the table, I now have many civie women friends (some with benefits) that I wouldn't have had before.

...according to Ralph Kramden:

my forties when things were going down hill quickly on the home front (romantically speaking. Prior to then, I would dabble with a provider or stripper maybe once a year. No experience to write home about.

...but I do like your peaches and would like to shake your tree. 😎

It's almost as though civvie women can sense from your renewed confidence and swagger that you're fucking really young women and so they have a curiosity about who this guy is. It's like the beer commercials with the second-most interesting man in the world with two 20-somethings.  Even though he's old enough to fall asleep and drown in his soup bowl if dinner runs late, women fantasize about what it is that these young hotties know about this old guy that they don't know.

Responding because of "demimonde".

"Being a whore has given me the confidence to say "no."

You could look it up.  But I won't make you.
"Disreputable or sordid in a rakish or appealing way."
Ladies like louche.  Pronounced "loosh."
It also helps that I'm a lush.

...to the wider range of possibilities. See, I  married my first "true love" and then endured almost 20 years of once-a-month sex (if I was lucky), missionary, no lights and NO oral (for either of us). Seems my "true love" was a Good Girl and they don't do that.

As a "problem" they understand I'm being facetious.  Of course it's a benefit and not a problem.

when I entered this world after my divorce 15 yrs ago. While I had a few torrid IRL relationships, most were more vanilla affairs where I brought the experience to bed with a few gals admitting they never had an orgasm,   and that they fucked more for their partner than themselves. I actually was doing the same, but by enjoying a dominant and serving role without really understanding that fact.  

Oh yeah! They know, believe me they know. Back in my day and even now girls have a sixth sense that subconsciously tells them that you`re getting laid on a regular basis and they become very intrigued. It`s almost like we`re emitting some kind of scent or pheromones and oh brother do they ever pick up on it. Mix in some confidence and a little swagger and the whole playing field changes to our advantage.
Speaking for myself I can remember times when I was in a bad slump and couldn`t get any booty no matter how hard I tried.  Don`t think for a second that they don`t pick up on that too.  To get out of my funk I would look for a bimbo or two who in no way would ever turn me down and sure enough after a couple of boinks the confidence and swagger would return.

Although I've always been willing to cheat, married life in the civie world doesn't provide many opportunities and the selection is limited to those who inhabit your little world.  Nevertheless when your horizon is just 10 feet away, you fixate your fantasies on what is in your field of view.

there is no "t" in "mensch."
Anyway, that is less likely than my being recognized as a douche.  A louche douche.  Nice ring, eh?

"a group of people on the fringes of respectable society"
I don't really have a problem with that term - it's a widely used if judgmental descriptor in this World. I tend to use "life beyond the veil" more - same thing I suppose but without the judgment  

Personally, I'm just fine with being considered on the fringes of same, and even with being judged for it.

I get that the experience has been positive for all of you, as it has for me. I've met many lovely women with different motivations and aspirations, the whole range of personalities you find in any group of people, and that's made me see sex workers in a more realistic and humanistic way. But in a certain way, I find that I objectify women more than I did before the hobby. Before, when I would see women in public I might think "she's beautiful" or "she's got a sexy way of standing/walking/running/whatever" but now I think "wow I'd like to have sex with her" because it's ever so easy to go search on TER for someone that looks like her or at least reminds me of her. I know it sounds a bit creepy but it's not a big change, just a subtle difference in my perspective that I've noticed.

Or a louche lush.

I've always been sexually confident, but used to hide the kinky fetish stuff from civvie guys. Now, I'm up front about the fact that I'm a sexually dominant woman. It's too much work to hide the thigh high boots, whips and sex toys.

I find since starting in this a little over 2 months ago I have a renewed  lust for life, health and happiness... I can feel my old self coming back... I have spent years in a misriable marriage and is effect on me has been profound ... spending time with people who even if they are doing their job make me feel Wonderful is life altering  

Some of the ladies, when you get to know them better or if you read their comments on TER, will tell you that that's an important and satisfying part of what they do. It has had a similar effect for me.

I won't try to copy the Hebrew letters, but in the glossary it's mem, ayen, nun, tes, shin--m-e-n-t-sh.

after I got married.

And "Tu me manques"--I've read the expression but you're right, the literal meaning really takes it deeper.

I've always thought that there's a great therapeutic value to this underworld society we participate in. Just the value of human touch and connection in itself is very important!! So many providers that I've seen have told me in many sessions the client mostly just wants to talk and have someone listen to him.  

...my laughter is louder and my demeanor more open and confident. I've met so many encouraging, charming, and chivalrous folks that it is difficult to not embrace life with full arms and live it to the fullest.
 
Plus, it helps that I am a Scorpio woman and so if any of that means anything to you, the demimonde definitely satisfies the carnal desires

I realized when chatting with a newer helix that since I've spent pretty much 100% of my adult life on these boards and in this lifestyle, I can't really identify any changes in my personality due to being here. I feel like it's simply who I was always meant to be

When a man is in a serious sexual drought and gets so desperate he'll hump a ham sandwich, that frustration radiates off of him! And no, no self respecting woman wants to be with a man who she suspects has low standards.  

It has let fantasies and exploration in the sexual avenue possible. More comfortable with my own sexual freakiness.