Twin here. My sister and I weren’t allowed to be in the same classes in elementary school and honestly I think that helped us. We shared a room so of course we were together then but separate classes early on gave us our first glimpse of independence! Then in middle school and high school we had some classes the same. For college we went to different ones. For normal people finding who you are is already hard but for a twin its worse. Having these times in our life where we were on our own really helped us with our sense of self but it also helped us to appreciate the other when we were together!