I work mostly menial jobs, and when I get bored I quit or go very part-time and get a new, more interesting job (sometimes it’s just interesting because it’s new). My jobs either a]keep me constantly moving and solving problems or b]come along with plenty of down time for me to be reading, learning or talking to people in between customers. Waiting tables, tending bar, being a barista, working retail (in the right company and department, where you enjoy interacting with co-workers and customers and have plenty of challenging tasks), teaching yoga - all can be quite interesting, as well as being low-stress and easy to excel at. At least for me. And picking up a new job in the same line of work is almost effortless once you have experience. I can go anywhere in the country, if I feel like it, and get another serving job which will support me in style.
Most bright people I know who, like Sister Vigilante, work low-stress office jobs and aren’t particularly ambitions - use their higher-than-average brain power to spend perhaps 2 hours per day doing the required work. The other 6 hours of the work day, they are therefore free to fill with whatever they like - often learning about new things on the internet. Or just fucking around on Facebook and the Straight Dope, whatever.
Life is really what you make of it, my mind is constantly active and I find new things to learn and do all the time no matter what I’m doing to make money.