Mom: Do you have a pizza cutter?
Me: I have a big knife.
(I hand her my largest knife, it's reasonably sharp)
Mom: I'm having trouble this is really dull.
(I look over and she's attempting to saw through the pizza as if the knife is serrated)
Me: Uh, give me that.
(I was able to use the knife for it's intended purpose of cutting down hard in a single slice to cut through the crust, but AHHH! You made it to what age and didn't know this?)
(This is probably due to my mom not learning how to cook much at all until after she met my dad and he taught her, but he was not a good teacher for most things)