Did you ever actually do this work?

Do you remember what browser testing was like?

Remember the quirks of browsers’ different understanding of transparency, of z-index, of events, of DOM compliance?

I think the suggestion that getting it right could take a week in the context of a particular application is actually not particularly hyperbolic.

Mind you, I was doing cross-browser testing long enough ago that I am one of those people who can say they independently invented AJAX in-house.