Ha, initially misread your question as its opposite (~"would reading technical/non-work related books in my spare time be a waste of time") and immediately thou

Ha, initially misread your question as its opposite (~"would reading technical/non-work related books in my spare time be a waste of time") and immediately thought no, of course not! To me, doing non-work related things outside of working is what makes _both_ activities things fun. Don't be hard on yourself for not spending every waking minute of your life working, preparing for work, or feeling bad because you "should" be doing one of those two. That's a very quick way get burned out. YMMV, but in my experience, even if you want to optimize your life for doing the best work possible, not working all the time is a winning strategy!