Yes, the second bit is true, for me - I am much happier as a consulting CTO than I ever would have been as a maths professor (abandonment of the latter career is what I meant by "leaving mathematics"). I guess I have to thank Berkeley for helping me to discover this fact relatively quickly.

I did not mean to lump maths and Berkeley together - I happened to leave both at the same time, but that doesn't mean I had to, or indeed that this was necessarily best for me, or would be best for others.