1. How to care for another human being who isn’t related to you, and who you don’t love just as a friend. Because really, at the base level, that’s the primary thing your first love teaches you. How to love someone romantically. It’s a hard thing to get comfortable with, especially when you’ve never experienced it before, but with a first love, it’s so exciting that you make it easy for each other.
2. How to be completely, 100% comfortable around a human being and know they’ll love you for it. Because it’s hard to get that close with people – even friends. It’s hard to get to the point of comfort where you feel like someone could love you through anything. It doesn’t happen quickly, but when it does, in those moments, you feel so lucky to know that love like that exists.
3. How to treat someone as your go-to confidante when you love them romantically, instead of platonically. Up until your first love, the only people you’ve ever been able to share secrets with have been your siblings or other family members, maybe, or your best friends. To feel like you can share with someone else – someone you know loves you in a different way – makes it an entirely different experience.
4. Realizing you can be best friends with a significant other. Because that’s what they become: your best friend. In your first relationship (or in any relationship), you don’t become a pair and then automatically become best friends. In fact, I would say you become a pair first, and then realize, maybe months down the road, that they’re your best friend, too.
5. That love will never be smooth sailing. And there will be fights, and challenges. You will never know it, and truly believe it, until you’ve experienced love and learned that, unfortunately, it isn’t movie like. But in that same step, you will learn that there is someone who will fight for you, and someone you’ll fight for.
6. How to comfortably discuss your doubts. And be honest, and say what you really feel, even when you think it’s the wrong thing to say.
7. How to cry on someone’s shoulder. Your first love teaches you to be comfortable enough with them to want to show them when things hurt you. They make you want to open up, even though that inevitably means you’ll share the hard things in your life, not just the positive ones.
8. How to offer someone a shoulder to cry on. How to be there for someone in a way you never really knew you could be.
9. How to shield someone from something you know will hurt them. You don’t really realize you have a protective instinct over the people close to you until you fall for your first love. It’s when you learn that you can feel strongly enough that you never want anything to happen that will hurt the other person, even though that might not be realistic.
10. How to feel fulfilled even after the chase is over. Learning to be satisfied from the actual relationship, as opposed to the initial flirtation, and the first kiss, is harder than most people realize.
11. How to leave. Unless you stay with your first love – which you absolutely might – you ultimately have to learn to leave. Which means you also have to learn to accept when things aren’t working.
12. And how much it actually hurts to leave the first person you’ve ever loved. There are few things harder than holding someone, or being beside someone, and knowing that when you walk away, you’ll probably never hold that person again. It makes you not want to move an inch, even when you know it’s the right thing to do.
13. How to get used to calling someone a boyfriend, or a girlfriend. And accepting that that can be comfortable and okay with you. You realize you can fit in that role, while still identifying as your own person and not just someone in a couple.
14. How to be vulnerable. And how to show it, and let someone in even when you know it means they could hurt you.
15. How to miss someone. Because, inevitably, you will miss your first love, whether it’s because you do long distance for a while, or because you break up. Missing someone you have only recently learned to love feels completely different from missing someone you’re related to or a best friend.
16. That you can make things last. That you can comfortably be in a relationship for longer than a couple of weeks. That you can trust someone enough to want to stay with them. And that even if you break up, you can know in your heart that your first love will always be important to you, which is lasting in itself. 
