I discovered that my fingers, other than needing to re-develop calluses, largely remember how to play the guitar.
For example, my wife and I were talking about playing Crazy Train by Ozzy. I remembered that I was once able to play it. I looked up a tablature file for the song online and started playing, but I kept having problems playing the riff as-written. Once I moved some of the notes over a string, I'd realized I was playing with a different fingering when I'd learned it almost a decade ago.
I find it interesting that, other than a little bit of speed missing that I'd need to regain and an urge to explore new things, how deep the memory lies. All of the chords and scales are where they were and my fingers remember where they were. I can still change a set of strings (my strings were nasty sounding after years of decay) and whatnot.