I looked up Tony Levin for shits and giggles,
and ran across this article. One thing stuck out at me (when asked if he had plans to retire or step back from the "life"): “Life will undoubtedly impose some rules on me I haven’t thought of,” he said, but “I’m lucky to have my health and what musicians want is to keep doing what we do. The people who can’t understand that are people never lucky enough to have a profession to occupy that part of your mind and life. It’s big for anybody in the creative field.”
Especially with some of the older bands we listen to here (I think this last came up when talking about Yes and whether Steve Howe should "hang it up"; I know it came up with Kiss as well), this comes up a lot. I think music is in certain people's blood. Sure the touring, maybe, can stop but I don't know how you just walk away from something that is an emotional part of you. Some have done it, of course - REM baffles me, frankly - and in other areas artists have made changes - Steve Martin, for one, walking away from stand-up almost completely - but it's hard to give up what is a part of you.