I started dating at 13 and had my first boyfriend at 14 my first serious long term boyfriend at 15 who I dated for almost 2 years then some other boyfriends and guys I was seeing informally.
I met my now husband at university when I was 18 and knew very quickly what an amazing catch he was due to my experience with guys and so knew we would stay together and we have. I used to feel like I wish I hadn't wasted my time with the other guys but really they all did serve to show me things I came to know I wouldn't want in a long term partner such as guys with controlling abusive behaviour, guys who were just unreliable and uncommitted, guys who felt they could do better or were paranoid that you would.
Sure I got hurt at times and had a bit of teen drama in my life but I was also young and it was easy to bounce back and at that age there are no shortage of interested guys as most people were not yet paired up.
Its true that I have never been single / not dating in my adult life but after I got together with my husband we still did long distance, and we both lived over seas separately for work and study so we have each lived alone and had our own lives prior to living together and marriage.
I knew other women who didn't date till university and a common pattern was to get serious with a guy stay with them for the whole of uni, move in after graduation. then over the next few years get fed up of them, feel like they were missing out or they got fed up with the boyfriend not proposing, still behaving like a student and they'd split up have some fun years but then struggle to actually find someone else to settle down or have kids with. Quite a few of them never did find a long term partner and aren't happy about that.
I don't know if this is true but I wonder if dating younger as a teen has a benefit of letting you get dating lots of guys out your system, trying out different relationships and people at that age finding what works, what you don't want and then being able to spot a good thing when you see it and holding on to it?