Lori has a point that sometimes a good workshop will get us motivated again when we get a little depressed, or wonder "why bother."
I think of piano lessons as a journey and not a destination. I'm going to post more about that on another thread.
We all have low points. Several years ago I was ready to throw in the towel, not because of my students or parents, but I was just so TIRED of the same old thing. I got over it with some good workshops and some new music.