Now people have posted I've seen some interesting ideas & it seems pretty cool except the school part.
Perhaps you could have other ways of earning skills, like fists (default), dodge (shielding), license needed for mounts(magic), theiving (sword) stamina (speed, you start with 0 stamina the more stamina the faster you move), climbing (axe) cooking (fishing), hunting (club), throwing (distance)
All the ones in ( ) are replacements for the default, not necessarily doing the same thing.