How do you know he is the one ? How do I know the guy I choose is the one ?
You will know.
But not that soon.
Not as soon when he chased you even he was engaged (even when you actually know he admires you for years). It could be he was just trying to flirt around. But you say.. see ! he didn't back off even a bit. He arranged so many meetings just so you two can meet. He texted you a lot. Well, okay. But that still didn't mean anything.
Then by any reasons, he broke up with his fiancee. But still, you couldn't tell he is the one yet. Then you two are in a relationships. Being in a relationships is easy, he likes you, you like him, then you two have a date. You still couldn't tell he is the one.
But then his friends started to tell you that he never look as happy as this before. His friends started to tell you that for the first time he seems really in love. But hey, maybe it was just a honeymoon phase. So let's not to exaggerate about it. Because as time goes by, you two will face obstacles. There's no guarantee the butterflies in your tummy will keep alive (besides, you know you are not an easy person to be with).
Then you two dated for years. He was still as sweet as before. He texted you everyday and every time (even when he was busy watching his favorite match on TV), he said he loves you every day, and stuff like that. He told you about his dream to marry you and to spend his life with you. He wanted to be happy with you.
But then here comes the exciting (well, not really) part. His family disapproved you two by any reasons. Then you can clearly see how much he loves you. He couldn't sleep well, he couldn't smile, he couldn't think, he lost his spirit to work because you are the only reason he works that hard just so he can marry you. He was on his lowest point of life. He said how he understand why some people remain unmarried, because he started to think that way if he couldn't make it to be with you. He told you that he had been in too deep he wouldn't wanna anyone else but you.
Then you would lost your patience to wait for the situation to change. You wanted to leave but you can't. Because apparently, being deeply loved by someone really feels so good. He begged his family. He told them how special you are, how different you are with others he had ever known, how in love he is with you, how he could go insane if he loses you, how you become the reason of his happiness.
Then you will know.
You will know that he is the one. You will know as you see how ones can struggle that hard and that far for you. You know he is the one, because he makes you the one, as well.
That's how I know he is the one.
He proves it.