After 40 years with the guys of The Last Call Band I've been saying when we started, the trouble was LEARNING the music. Now, the trouble is trying to REMEMBER the music!
I never was at the level to actually play in a band on a stage, as you were/are, but I can sure relate.
I alway been drawn to fingerstyle solo stuff. In the early 70's, while in college, I needed only a few weeks to listen/rewind/listen again to a John Fahey solo on my portable real-to-real tape player/recorder and pretty much learn and remember and actually do a pretty good emulation from start to end.
Scan forward 30 years to my early 50's, (that would be 15 years ago) I took up the guitar again. New technologies allowed me to learn many tunes from TAB, MP3's, slowing down without changing pitch, and record myself to compare my attempt with the original. After a few months to regain finger strength, dexterity and finger tip callouses, I began to do pretty well. My fingers still could remember and play pretty complex stuff. Better than in college actually. But what changed over the years was a now epidemic penchant for frequent blow-outs while playing. Yeah, there are those sequences that always will cause trouble. The ones forever beyond my ability. But even simple sections of songs were never safe.
Now at age 67, I have instead taken to playing/learning new songs by reading directly from the music or tab without looking at the fret board while practicing. Been a real (very frustrating) adventure learning to move positions from up/down between the 1st fret and say the 7th or 9th or 12th without looking. Getting better at it, but I'll never be a natural. But the most significant result of playing directly from the written score is that I am not able to memorize as before.
But the real reason though is: ADVANCING AGE!