I have a relative who holds the view that time is illusory, especially when hen is under the effect of some toxin.

I ask hen: when did you figure this out?

The answer inevitably starts with a story that happened many years ago and I point out that if time were illusory then there is no appropriate way to answer the question.

Because hen is drunk or stoned, I get to do this multiple times. It's not the time is illusory, it's that hen doesn't remember.