There are so many valid points throughout this thread. As a new player, I'm am enjoying myself so much right now that I have to pause every once in awhile and make sure I'm taking care of the business in my life.
I'm playing simple pieces from the study guides I'm using, working on my technique. I have tried a few more difficult pieces, not being able to resist looking ahead to see what's to come. Several times I've had to back off to where I should be concentrating. Everything I've tried has been relatively simple, and when I return to something after a week or so, I've found I can play it better than before whether it was something that I felt I had done pretty well or something that was too much for me. I suppose that's one good thing about being a beginner - there's much room for improvement.
I'll definitely be considering the good thoughts presented here. I hope I'll naturally recognize that the music is too hard when I'm frustrated and not enjoying myself. But I suppose as one improves and the music gets more challenging, it may not be so clear. I am planning on finding a teacher, but first I have some personal things (daughter's wedding, for one) to get through. I certainly don't want to get to a point where a bad choice makes me want to put down the guitar.

