This happens to me a lot on more difficult pieces.. I'll be sitting there working it out and getting sort of close, but completely missing a few parts. Then I give up. Then maybe a few days (or in some cases, a couple weeks later) I go back to and and BAM, first try nail it all (including the parts I hadn't quite figured out yet). Ever happen to you guys? sort of related, but not really, I remember a long long time ago when I was first starting bass I was struggling to play the bosstones' someday I suppose. The other day I was on a kick of playing old tunes and that one came up. It was so simple. Gotta love it when you realize how much you've improved.