The smartest all around renaissance-savant-genius I ever knew personally was a social worker by profession, who often moonlighted as a lounge pianist. He had a lot of hobbies, and is a published author and recording artist. His musical ability is supernatural. One of his party tricks is taking the sheet music for two random difficult piano pieces, placing them side by side, and reading/playing them simultaneously while mentally adapting each in real time so it sounds like a well written third piece. He is a human GAN.

The smartest software developer I ever knew hopped around several FAANGs and MSFT, sort of round robin, driving up his pay and rank. Somewhere along the way he bought a building and became a property manager on the side.