I've expended an inordinate amount of effort trying to get a rewarding job, more-so than at any of the jobs themselves. It's not a given. If you've taken a career trajectory that employers find don't match the pattern they are most familiar with and place a premium on, you will have a doubly hard time, as you're competing with those who haven't.
Free time is what there is for me, and though I don't think of it in "productive" terms, I do think it's important to bias towards action rather than passive consumption.
