@georgetakei when I need to school someone on how “they” is used as a singular pronoun, I use the anecdote:
“A person on a motorcycle drove past me, and then they turned right.”
I can see the gears churning in their head as they work out, was it a man or woman? Maybe I can’t tell, on account of the helmet. Or maybe IT DOESN’T MATTER!
Tellingly, it’s worth noting that you only need to know someone’s gender if you’re planning on treating them differently based on the answer.