Crushes can fade, even romance (so big in the beginning) can fade, but true love lasts longer.
A big part of it is commitment. Relationships, even married life is not all stardust and moonlight. Sometimes the reality hits when two people living together have to deal with such mundane stuff as bills, raising kids, sometimes moving, switching jobs, all that fun stuff.
A lot of people try things out, like "playing house" to see if they can put up with each other. Sometimes it works, sometimes not. Sometimes best friends move in together, and in a short time end up hating each other. Commitment means sharing everything, from dreams to dirty socks.
Love is a wonderful thing. To love one another, the feeling of being in love, and two hearts coming together. I'm blessed it happened to me, but it can get rough sometimes. Being in a relationship can be a challenge for some, because you have to start thinking, instead of "What's best for me" to "What's best for US".
Commitment, sacrifice, it can get rough sometimes. I'd be lying if I said my wife and I didn't have a few disagreements over the years.
And sometimes the people you love the most, can also make you the angriest.
That's where patience comes in. And tenderness. And remembering why you were together in the first place. We've been married almost 17 years, known each other 22, and we're still figuring things out.
It's not always easy, but man, it is so worth it.