I got out of playing for a while in my mid 20's, then picked back up again in my late 20's playing a lot or accoustic Folk and Irish stuff.
Recently, with the slow economy, I was out of work and sitting at my computer watching classic rockers on youtube. I though, you know what... I can do that! That lead me here to GT!
SO after all that comes my answer (sort of). Like Frankht, I have small successes every time I practice. When something clicks and I get a technique or riff I had been troubled with. I have made big success since I have started. I am more comfortable noodling around in different patterns,(let alone know the patterns) bends, double stops, slides etc. I can jam along with the jam station for a bit without getting lost. Soon I will have the success of getting timing down and not getting lost when when I play off, or in between beats.
My ultimate success is though, to be able to play the music I love. To her a song on the radio, think.hmm i think ill learn that one, and learn it. Also, to be able to put together some of my own music and even blend from all the genres I like, rock, blues, metal, trance, folk, accoustic. Maybe as a band, or maybe just at home in my own little studio.