[coldtea]

>Is it that he reads constantly and eclectically?

No, it's mostly that

(a) he has the will to ventures in various fields

(b) he has the money (from his early ventures) to venture in various fields

(c) he hires people who know their stuff in those fields

He doesn't have to come up with anything resembling real innovation (a new technique or process) himself. He just have to give his stuff the general direction and push them towards it.

Having a technical and business background helps, but don't imagine any Tony Stark like lab research on the technical level done by him personally.