It's not doing less, it's actually doing anything, and yes it's very related to age and view on life. As You, in my twenties I would burn into flow to swallow a lot of things. Now I don't. The irony is that I was quite stupid younger, and have a much much broader and stronger understanding of abstraction, geometry, holism etc, all things life teaches you with time. But .. unnecessary complexity and other goals have taken hold of my `libido` if I may say so. My comment wasn't much about finding drive again but also accepting that passion isn't always there but life requires you to be able to work. I find that people that weren't passion driven at first thus spent a lot of time working on things that were tough or unrelated to their dream and are more stable in the long run.

I'll second that... pointless complexity in your life is an unnecessary drain on your energy. It just adds to your burnout.