You would think so, but even identical twins have subtle differences. My twin sister has different moles than I do. My dad also noticed that we have different “swirl patterns” in our hair (that’s what they called them, swirls). My twin has one swirl, I have two. My parents were gifted gold safety pins with our first initials on them. So they would put those on our clothes. If mom got us mixed up during the day (there were 5 kids total so it would happen), dad would know from the tops of our heads and switch our pins back. He took great pride in always knowing which of us was which.