[sadcodemonkey]

Yes! I've found this to be true too.

Early in my programming career, work was a mix of repetitive, somewhat mindless tasks (implement this webpage, fix this bug, etc) and more intensive, thoughtful activities (figure out a better algorithm for something, help architect a solution for a problem).

I think this is healthy. We can't be "on" 100% of the time. And I'm convinced that during those times when we're doing mindless tasks, our brains are actually working in a different way that we're not conscious of. It's like how a solution will sometimes come to you in the shower.

I don't think increasing intensity of work is the single cause of burnout, but it's definitely a part of the equation, and one that's definitely overlooked.