So you think you've loved somebody before?
You haven't.
The wide canyons of heartache, the effusive heights of confession, the dizzying grip of a hand in yours that you want to be welded there infinitely. The feeling of home, of belonging; the sheer terror at the thought of losing that home in a flash-bang moment of accident or a long, consuming illness.
The mystery of it all, the endless questioning: motives and meanings and thoughts and feelings. Things you know but don't yet know. And you only pick them up as you go because you're still a kid and you're going to have to learn a hell of a lot from her.
You're gonna learn about courage, real courage, not just blind indifference to your own mortality. You're gonna learn about heart, and pain, and sacrifice. Trust. Belief in a larger power. A whole galaxy of information you didn't know you needed. A whole universe of kindness and goodness because people really are good, though you haven't seen it yet. They are. She is.
You're gonna learn about family.
Why they're important, why people have them. Why people kill for them, die for them. Why people devote time and space and credits and their lives to them. It's unfathomable now, sure, but you'll see.
And you'll learn about the pride of a long love, of decades together in a harmonious querulousness that stymies everyone but the two of you. Nothing will be new anymore and there's a kind of excitement in that, too. You're a head-on speeder collision of commitment and trust issues now, but you'll figure it out.
You have no idea what you're about to do. If you kiss her, you're going to fall harder and faster than you ever thought possible. It's going to consume you. You will balk at its suddenness and you'll try to cling to your old life but no, guy. No.
You're about to fall, headfirst and fatal. And you should do it anyway.