I go through cycles. I'll have a long stretch where I come home and I'm just fried and can't do anything that takes critical thinking. And then I'll go through a period where either work is more boring or I've found something to do on the side that's so exciting to me that I have tons of energy and focus on side projects.

One thing I've been doing for the last 2ish years is having side projects that are really far removed from my work. So for example a lot of my work is infrastructure automation and related problems, so I've been doing some side projects learning basic electronics and hacking on microcontrollers. Figuring out why my I'm getting weird readings on a temperature sensor is a great break from figuring out why my load balancer didn't do the right thing.