This is the time of year when I need to start working on contracts, and ask myself if I want to continue. It's a slow time and I tend to forget how much I enjoy playing out, and think more about booking,equipment,setup,travel etc. I think a tell tale sign for me, aside from loss of call for what I do, is when I go out and see another live performer. I always feel I want to be playing, not just listening. When kicking back and downing a few while listening without any desire to play is enough, then I'll know.