How Does He Know You're The One?

Everytime I watch a movie or read an article that brings up the topic of marriage, romantic wedding, and couple stories, I have the same question that pop-up in mind : "How did she know he's the one? How did he know she's the one? What makes them so sure about spending the rest of their life together?"

Most women answered "I just knew it. You know he's the one when you stop wondering whether he's the one or not." Romantic. But that wasn't the answer I'd been waiting for. It just somehow didn't hit the spot. I need some logical explanation.

So I asked a good friend of mine, whose recently got married, "So tell me, how did you come up with the idea of marrying her?" And he responded:

Because she's worth it. She worths every second I spend on this planet. She worths the extra lembur time that I have, she worths every single tears that I shed for her to be happy and settled. And about her being my wife.. the more I thought about it, the more I wanted it.

That's just... a perfect answer. Yet it leads me to another thought. "What does it take to make me worth that much?"