While I've programmed software for many years, I've only recently started doing so professionally and have noticed a bit of a problematic pattern. I hope this is the best place to pose such a question, as I am interested in others' experiences and solutions...

Writing software is, by its nature, a cerebral exercise. When coding for my own sake, I would do so until I was satisfied; even if that meant going all night. Now I'm coding in exchange for goods and services, on projects that are inherently uninteresting to me, I want to 'switch off' when it's time to go home.

Maybe you consider that to be a 'bad attitude', but I just don't feel that whatever I'm working on is worth caring about after-hours. Besides, my employer doesn't exactly have the infrastructure required to make out-of-office changes; I can't just clone a repo and even remote login is a PITA.

Anyway, the problem I'm experiencing is that, while I'm not particularly overworked or stressed, if I'm faced with a problem, my brain will work on a solution. Generally, it won't give up. Hence I can't switch off and, sometimes, the problem or the solution is significant enough that it disrupts my sleep. While, paradoxically, this doesn't seem to affect my coding ability, it can have a profound impact of the rest of my life. I get increasingly low as I get tired.

So far, the best solutions I've found are writing little notes on the matter (and, say, e-mailing them back to my work address) and exercise. Neither of these can switch me off entirely and, as the week progresses, exercise especially becomes untenable due to tiredness.

TL;DR How can you stop from being a coding zombie?