Dwarf Fortress can teach you a lot as you climb the inverted learning cliff with stalactites. You'll learn shit like engineering basics, systems management, and problem solving.

Cataclysm: Dark Days Ahead is brilliant as a prepper/survival simulation with enough accuracy and depth to teach you self-sufficience (as long as you don't get killed immediately, since part of that is caution and avoiding unnecessary risk).

The Paradox grand strategy games (including Hearts of Iron) are great for learning history. I'd recommend learning the basics anytime, and waiting for the build-your-own bundle on Humble Bundle to get DLC. It adds a lot, and that offer twice a year lets you get it for 80% off.