>Now, I'm in my 40s and I'm like "Done with work; I think I'll go for a walk and then take a nap."I'm in my early thirties and never had any side projects. After busting my ass coding like hell for 6 years in university and after 8 hours of coding at work per day, I was always seeking to do non-coding activities in my free time: trying out new hobbies, going for a walk, having drinks with friends and going dancing, dating, witching a movie, jerking off, cooking, reading, hiking, SLEEPING! etc.
This hurt my chances of getting into flashy well paying VC funded agile scale-ups where every applicant was a 20-something with a huge GitHub portfolio, but, and I hope I don't offend anyone, life is too short to spend my free time doing things I don't enjoy, just to look good in front of $COMPANY, that will lay you off the next day if 'line goes down', so I narrow my job search at companies where coding is done for the paycheck, not for the lifestyle.
I do spend my free time sometimes tinkering with various linux distros and DEs, and sometimes reverse engineering, but moistly working on hardware projects to build to increase my comfort around the house like a tap-water to air apartment AC cooling unit for the summer. I've always been a hands-on kind of tinkerer, with physical things, not with code, since I can't touch it.