[cafard]

"The bulk of [your] time"? Unless you have an independent income, this may be the bulk of your free time.

Off the top of my head:

a. Live where you can get by mostly walking or riding a bike. That will help with fitness. b. Take some classes. If you already know a musical instrument or two, I suppose you can learn another easily. From a given level of mathematical maturity, you can learn more math on your own. But foreign languages, drawing, and painting seem like skills you can use some help with. Community colleges, university extension programs, organizations such as the Academie Francaise and the Goethe Institute offer things that can help you. c. On your own, you can read plenty of history. d. Philosophy is worth reading, but requires some context.

Good luck.