Whether one should have hobby projects

Long time ago, when I was just studying and not being working, I enjoyed having my own projects to work with. Being primarily software guy, this of course was projects I could think of. Utilities, games, tools, anything like that. Lots of them, in fact. Some gained some interest, but nothing spectacular. I had plenty of time and energy for that.

Then I got work as software developer. Part-time at that point, but still. So now I am programming some four hours a day for work (plus studying, this being while I was still in university), and much of that (work) was actually learning about things around the main job as well - things like physical environments and how they affect signals, math around stuff, programming tools and concepts I hadn't encountered before and so on. Fun stuff, really. I always love to learn new stuff that interests me, and money is kinda big motivator for learning.

Then I graduated and previous part-time gig became a full-time job. And suddenly I didn't really have any energy left for my own projects any more. Will, sure, but energy, not really.

Over the years I've figured this out in more detail. Part by reading, part by experience.

It's said that programming is creative work. I absolutely agree with this, even if you are dealing with what could be called boiler plate code. There is just so much of creative effort you can squeeze out before it gets depleted. While I may not be painting Mona Lisa, or sculpting David, there still is is structure of program I'm writing that I have to keep in my head while working. Small problems are almost nothing, but big frameworks, bug structures, still existing only in my head, are fragile things. Keeping them in my mind is an effort, and a very taxing effort at that. And badly timed interruption can smash entire thing to splinters. There is a limit on how much you can keep such thing in your mind.

My personal hard limit seems to be at around five to six hours. After that there is a wall I run onto, and no matter what I do, I will not be productive software developer again until after proper rest - that is, a good night's sleep.

I can do other things though - say, assembly line type work, or anything completely different that software stuff - but then again, at my current position I am kinda lucky I have that escape route. If I were working in usual 8 to 4 office setting, there might not be anything else to do but sit there feeling useless.

Documentation, testing, all that - it's essentially same work, in different format, with different difficulty applied. I can try to do it, but in the end the quality will be sub-par. It's better I don't even try. So, five to six hours of serious work. And I am not even surprised that I don't have energy for hobby projects any more after that, not any more.

I'm not the only one, mind you. The consensus on the field seems to be that six hours per day is already pushing it.

Now, common theme in industry seems to be that one should have those hobby projects. Employers seek to people with those interests.

Now, wait a moment here - as an employer, you want that your people have energy left after work day to seek out extracurricular activities? Really, do you really want that your people you employ just waste their time - time you pay for - doing whatever, only to have enough energy for those hobby projects too?

Really?