How do you know the person is right for you?

Being a guy, I don't claim to be any kind of emotions guru or anything, but I do know this: I was in love once. Her name was Elizabeth, she was in my senior class, and we only dated for about a year. But, at around the second or third date, which was just playing skyrim at my place, I could tell I was in love. Because I, as a man, felt a connection to her beyond the mere physical, oh she's hot level. I don't know if it's any different for women, but that's how I believe a man can tell that he's found something special.