Is it possible to love?

The feeling we describe as love is extremely complicated. There isn't really a set definition for it. But does love truly exist?

I personally believe it doesn't. When you think about it, anything we "feel" is a response to a physiological reaction. Feelings are a complicated subject in psychology regardless (any psychology majors out there I'd love to hear your opinion!) but love is a step above other feelings. It's more intense. One big thing that fits into love is lust. However, in the end, lust is simply the drive to procreate. We all have sexual desire. But there's more to what we define as love. It's a person we want to see every day, spend time with, talk with, laugh with. There's something about their personality traits that attracts us and causes us to bond with them. But just because we deeply appreciate that, does that mean we love them? We become protective in the sense that we want them to be okay, to survive, and are willing to make sacrifices to do this. Animals do this, too, when protecting their young. Dogs tend to do it with their owners. That's more of a familial love than a partner love. And that's another thing, why do we have to distinguish between different types of love? Humans have an ever changing mind.

But in the end I guess my question is how could a person truly be in love with someone else and want to be with them for the rest of their life? I mean, I've been extremely affectionate of people before, I've gone months on end thinking of the same person multiple times a day, wanting to be with them and see them all the time, getting that release of endorphins in my brain when I see them, gotten those butterflies in my stomach whenever I'm with them, but despite all of this can that be love as the majority defines it? I feel as though after a while you would get tired of a person. I've heard people say that marriage keeps people together as they fall in and out of love. But is it truly love if you fall in and out of it?

I'd like to know your thoughts.