"Forcing yourself to spend your free time on something you don't enjoy to the nebulous end of "self-improvement" will accomplish nothing and make you miserable."

You have a financial and ethical obligation to your employer to spend at least some working time thinking of process improvements, and part of that is self improvement. Don't be "that guy" who spends 10 hours a day on youtube and than has to spend 6 hours of overtime frantically trying to keep up with the 8-5 plodders, but you are literally failing in your obligation to your employer if every time you start to lower your nose to the grindstone you don't at least put forth a minimal google effort for a way to eliminate or automate or shrink the very grindstone you're about to impact. Don't let your employer down, do at least a little self improvement every day. If you feel guilty about it, turn one of your ten daily facebook/twitter/HN breaks into class time, just one is better than nothing.

Programming is not a piecework manual labor job. You're supposed to be learning.