Of course not, but it's amazing at how many things come back to you when you start playing it. It's more of an ear trsining than memorization really. You get to "hear" where the next chord is coming from just by sheer repetition of so many similar changes.
Sure, the C&W & 50s tunes were the easiest because of the simplicity, but even some of the more interesting changes come back if you get inside the chords while you play it.
I forget LOTS of stuff ... daily, but I'd still rather play a request as soon as it's asked for rather than let them see me search for a chart. Even, if my "hap hazard" arrangement could be better .... sometimes the spontinaity of the moment is more valuable to me than a missed #9/13 chord. I still like the "seat of my pants" approach for most things .... except Bridal dances or showcases. If it's just a dance, and they're drinking ....... they get what comes off the top of my head, and they usually like it !
(which ISN'T hair !)