Why is a click event not stopped by stopping mousedown/mouseup?

Coulda sworn this wasn't how it used to work, but with jque开发者_运维问答ry my click event is firing even if I return false on both mousedown and mouseup.

Because a click event is a mousedown followed by a mouseup. Stopping/absorbing the ancestor events don't change the fact that they happened, and having happened is all that is required to trigger the descendent.