Maymay: If someone suddenly became invisible would they be able to see other invisible people?
Me: um...are you seriously asking me if an invisible person can see other invisible people?
Maymay: Yes. Can they?
Me: Well, I've have to guess no because they are invisible.
Maymay: Exactly. If they are invisible they should be able to see other invisible things. Clearly you can't see invisible things if you're visible so if you're invisible you should be able to see invisible things.
Me: My brain hurts.