The difference between "love" and "in love".

I did my share of dating before I met your mother. More than my share, actually, given that I had long hair, a runner's body, a very good job, a promising career, and a gift for turning a clever phrase.

At one point, I had a girlfriend I really wanted to be The One. (To be fair, I wanted every single one of them to be The One, which probably explains why I got to date so much and so well. It also explains why I couldn't just enjoy dating, but I'll get to that in another episode.)

One day, I told this girl that I loved her. Naturally, I expected that she'd say she loved me back, but she didn't. Instead, she asked how I defined love.

In addition to being taken aback, I was stumped. I hadn't actually defined love for myself. I just figured that like porn, as the famous quote goes, I would know it when I saw it.

She helped me out, though. She told me that to her, love meant "appreciating in someone else the qualities you like most in yourself." And at the time, I thought that that was a pretty workable definition.

If I'd thought about it more deeply, I would have realized that by her definition, what I felt for her wasn't love. One of the things I admired most about her was the purity of her beliefs--something I didn't possess myself.

Since then, I've come to change my definition of love. And while it's still a little fuzzy, I have a better sense of what it means. Here goes.

Love is valuing someone for what he or she is. Not because of what he or she is, and not in spite of what he or she is. And it's not valuing certain aspects of a person. It's valuing an entire person for all the things he or she is.

By that definition, I love your mother. And I love you.

In love is completely different. In love is not about what is, it's about what you wish it to be. In love is about hope, while love is about knowledge.

This is why I don't believe in love at first sight.

I believe you can have incredible chemistry at first sight. But you can't know someone at first sight. You can imagine what they might be like, and if you're lucky, they'll turn out to be who you imagine they are. But the odds are very much against that happening.

Hope is a powerful thing. Which is why being in love is usually so painful. You're hoping he or she will call or say the right thing or touch you in just the right way because you're hoping he or she will turn out to be the kind of person you want him or her to be.

It takes time to realize that what you have may not be what you imagine you want. And it's only then that you can honestly evaluate what you have and decide whether to keep going at it.

For me, it always took four months to fall out of love. For your mother, it took two weeks.

For both of us, once the initial infatuation went away, we came to realize that we loved each other. Not because we're perfect, but because even with our annoying habits and faults and weaknesses and baggage from other relationships, we value each other completely. We know each other well enough to anticipate--and compensate for--the things we're not crazy about in each other.

I think the search for love is somehow inevitable. It's programmed into our biology and there's not a whole lot we can do about it.

It pains me to know that someday, you're probably going to fall passionately in love with the wrong person. Over and over. You'll lose sleep, sacrifice friends, compromise your career, and make some pretty dumb decisions, all in the name of hope.

But I also know that those are the experiences that will ultimately make you who you are meant to be, and that person will find real, lasting, true love. I hope I'm around long enough to see it. I''m excited to meet the person you're going to end up with.