Personally I've found it much easier to sustain creative stuff on the side while doing a non-knowledge-based job than a knowledge-based one. Mental exhaustion i

Personally I've found it much easier to sustain creative stuff on the side while doing a non-knowledge-based job than a knowledge-based one. Mental exhaustion is much more of a drag than physical. (Though the knowledge-based hours were longer too, which I'm sure was a factor.)