[fromMars]

We can't really know for sure. We have the anecdote about the workbook but what about earlier and did he absorb any of his dad's teachings or aptitude by osmosis.

Even if we accept he didn't he still went to college and had an unusual experience as an undergrad in being mentored by an excellent mathematician.

That he took a gap year in h.s. doesn't seem that noteworthy to me.