I was sitting in Government Center picking my one-pin tumbler over and over, waiting for the train and listening to a busker play guitar, when I realized I'd heard the same guy playing the same song, over and over, for... years. Train at the Park Street station; same thing - a singer this time, one I'd earlier pointed out to Ian: "In five years, I've heard him sing three songs. 'The Candy Man,' 'Singing in the Rain,' and the one you're hearing now." "Do you think that makes him happy?" Ian asked.
I don't know. Comfortable, maybe. You need something stable to measure your changes against. And stable doesn't always mean stagnation. I don't know if those two musicians think the same way. Granted, maybe they can't - they've tested these 3 songs to bring in the most money... me, I feel like I'm most optimized when I'm off-kilter and in constant motion. Another way of putting it is that the things I want to optimize for are always in unstable equilibrium.