あなた know when あなた look at them and get weak in the legs and that あなた can't breath when they smile at あなた または (sorry for saying a twilight line) it's no longer gravitey holding あなた to earth it's them. あなた think about him/her all the time and you'll know.
あなた don't know, really. あなた just have to trust yourself.
I don't think it's about shortness of breath または weak knees または anything. I think it's about understanding and the willingness to put up with their flaws, no matter how severe. If you're hoping for the person to change in one way または another, then it's probably not the right person.
