Yes, that's how he was able to build his house around a custom-built pipe organ. Also, though, many men of his generation leave the toilet-cleaning up to their wives. But he says he and Jill each have uniforms for this purpose.

(My toilet looks and smells much better now.)

Makes a bit more sense.

TAOCP sold more than 1 million copies over the years. Which doesn't make him Zuckerberg rich but wealthy enough to afford a house keeper if he wanted.

I haven't asked him but I don't think his book earnings are significant compared to his salary and pension.

Wealthy enough to have a pipe organ in his home on the Stanford campus! I'm sure he could afford a housekeeper if he wanted one.