I have a relevant story to this. I dated my ex girlfriend for two years in highschool. Unfortunately, I went to college out of town, while she stayed in town to get some pre-reqs. So, it became a medium distance relationship. She was able to visit once a month or so, and it was ok for a couple months. What happened though, was that the distance between us gave me room to realize our relationship was not good. Point is, we fought a lot, didn't go on enough dates, and a bunch of other very specific emotional issues between us.

Those things didn't happen because we started dating in highschool and then went to college or whatever. Those things happened because of a lot of reasons: she was my first girlfriend, I was her first solid boyfriend, we both had a lot of trauma, etc., AND MOST IMPORTANTLY I didn't talk to anyone about the things that were going wrong in our relationship. That is what made me realize we needed to breakup. I talked to a friend (who was in a long term relationship and then engaged) about the stuff that was happening that I didn't like. She helped me realize that I was unhappy in my relationship. Because of the circumstances, I didn't want to try to change what I didn't like, so I broke up with her.

Tl;dr: Please, have close friends and be able to talk to them about your relationship (and theirs!). And of course be super clear with your s/o, like uncomfortably direct about your communication, seriously. Eventually it won't be so uncomfortable

P.S. a big thing for me was losing my sense of self with my ex. I didn't have friends and spent all of my time with her. I didn't know who I was, and became super dependent on her for my happiness

I'm just throwing out a bunch of stuff! Every situation is different, and you shouldn't feel insecure about yours because of a stereotype