accidentally when I was 19 and started hanging out at the strip-club mid-day when I was in college on like a Wednesday or Thursday ....and learned about day shift girls, haha. Had a pasted on top fake ID with photo paper that i left/showed in a wallet for buying beer at the store (said it was stuck and even glued it in at one point) for me and the homies at will instead of needing older kids (used them for the liquor store) .

2for1 lapdances would turn into BBBJ or handjobs. Most were happy i wasn't an old dude on lunch break wearing sweat pants...or the over aggressive meat-head 20-something that gets damn near wasted for the night shift. Obvi I lied to the girls about my age so they wouldn't get in trouble for knowing.  

 
But full fledged hobbying with intent under no guise of massage or strip-club....meaning just the standard time&companionship was at age 25. Lets just say i'm between 25-30 now in days so there's girls i'm not old enough to see, lol. but it's not like i'm missing out cause I tend to go 19-24 as they remind me of bubbly college girls and I still like to have that type of fun so we have a chance to vibe more and I can probably do them better than their boyfriends

or are you the days before the internet.

If your talking about the days before the internet, then I started hobbying when I was 19.  
I worked near were was a lot of street walkers worked, so going out for lunch and a quick S&F was not uncommon

16 or 17 with SW's.

Got some extras at a strip club -- 22.

"Lingerie viewing" shop -- 26.

SW action -- 28.

"Relaxation center" and AOL chat room pay-for-play -- 30.

Yellow pages "escort" -- 31.

Ads on online ad and review boards -- 34