I don't like most of the responses here so I'm offer my own. Love is not found it is built.
My wife and I got married young. I'm 34 and I'll be celebrating my 9th anniversary in under a week.
Love is where all those things come together. We have the deepest friendship. We're weird in the same ways and we've basically developed our own brand of humor. I can make my wife laugh literally with a look.
Love is also a commitment to never, ever bail. It's unlike anything else. With friends, you still try to be good company or you wouldn't tell them the deep thoughts. But my wife and I can share anything. We're so intertwined that there's more understanding than judgment. We can say things we don't like about people, about the world, about ourselves. We can be truly vulnerable.
We didn't find love, we built it. From 25 to 34 I'm a phenomenally different person, but we're like two planets oscillating around each other. Our orbit influences the other, and vice versa. We never would have been these people if we weren't together. With most friends I feel like they may have some influence... But in marriage it's just undeniable.
It's a truly unique thing. But I will say I couldn't understand it until I had it. And I still don't. Dating for 4 years wasn't the same as marriage after 1 which wasn't the same as marriage after 5 and that's not the same as it is now after almost 9 years. It's always growing, always deepening, and it's just insanely personal at a very deep level.