There's something really fun and spooky about that teenage feeling of narcissism or indestructibility, like the idea that every night might be the night before the world ends.
There's nothing better than having an experience now that's the exact same thing I would've done when I was 16, like texting a really awkward "I like you" message to someone. The way you phrase it might change, but it will always continue to happen, and there's something really charming and calming about that.