Sometimes it can be easy for them.

By making yourself stand out from the crowd, or the average Joe, one can often become a memorable hobbyist.  For me, it's doing something outrageous and funny, like maybe modeling some super hero briefs.  I know a few ladies who will never forget the "Man of Steel" LOL.  Hey, once you reach a certain age, and embarassment is no longer an issue, it's easy to start thinking outside the box.  LOL

The brain is a muscle.. and only get"s better if  you use it. I always pick out something memmorable about my meeting with friends.. Most of my friends are near and dear repeats so that helps.... Some girls use a system. Some girls just fake it and others see only a handful and know who they see when....

It worries me that you can see 3 or 4 or however many and not remember them?
Dear god. Please at least make a mental note of thier name..

That leads to me mentioning my long experience as a climbing guide, which always seems to make me the "climber guy" in their memories.

Those are the ones with whom I don't have much of a conversation.  With the others, it is the conversation that they remember.

A funny story that indicates some ladies remember and others don't.

I saw a provider in August 2003 and when she came back out of retirement, I saw her again in September of 2007. She remembered my hotel from the prior visit, describing the unique entranceway that was sort of hidden and below street level.

I saw another provider in November of 2006, and when I saw her again in July of 2010, she remembered the name of my hotel and exactly what she was wearing (the memory for me was also vivid enough that I remembered what she wore as well.)

Finally, I saw a provider in June of 2009 and then again in July of 2009. She asked in July "Have I seen you before?"

Many ladies, while they may not retain your information, do keep a written ledger from week to week that will often include who ( first name only or nickname), how much and where.