Anything technical and application based can be learnt without. In my personal experience the best courses were the ones that looked beneath the surface, that a

Anything technical and application based can be learnt without. In my personal experience the best courses were the ones that looked beneath the surface, that answered "why" not "how"; so I would suggest only humanities and liberal arts. Take philosophy, sociology, anthropology, those can be almost life changing. Unless you're researching under a like-minded professor, studying anything technical at the undergraduate level is a waste of time because you can do that on your own. One exception: if you want access to the particle accelerator you might have to be registered in the physics department. I want to add I am quite impressed by your sensibility.