(I am not trying to change the subject)
A true story I remember clearly is that when I was in school, there was a pair of twins who looked extremely similar, but they were not born identical (this was actually a very rare case of 2 people who looked like they came from 1 egg that split but was actually 2 sperm that fertilized 1 egg), and every class I had with one of them, the next class always seemed to have the other in it. It was weird to start with, especially if I just had a conversation with one of them. I accidentally expected the other to know exactly what I was talking about, but instead, it just became a moment of awkwardness.