It's a question that people often want to know the answer to, but don't often have the time to ask: How do you keep programming fun?
When it's your job, day in and day out, to apply these concepts in rigid ways to achieve business goals ... that can sometimes suck the fun out of things. So how can you avoid that?
I have a lot of tactics for avoiding that sort of burnout (including a pantheon of half-finished hobby programming projects, and many non-programming interests), but I think that the easiest one is simply playing with code.
Find little problems that you can solve with code in a short amount of time.