What Is It About I Love You?

So, what exactly is it about saying I love you that moves a person to tears or more often terrifies one to death? It's just three words. Standing alone each word doesn't seem to shake us at all. Obviously "I" and "you" have little effect on any person. The word "love", however, you would think, would mean a little more to people. It really doesn't seem that way, though. I even call many of my friends by the pet name "love" and none of them bat an eye lash when the word is spoken. Without a doubt, there's only power in those three words when spoken together, in sequence I... love... you.
It's an extreme type of power that these words seem to hold, and frankly, it doesn't make sense to me. We freak out about saying them to a person for weeks, often months, building up this huge scenario in our minds about how it's going to be when we do actually say I love you, & then when we do, it's just disappointing. Either the other person actually does love you too and just says, "Oh I love you too," or they don't feel the same way and they say, "I love you but I'm not in love with you." Why do we torture ourselves? We wait for the perfect moment to say these three words for months and months. Why not just get the moment over with? It doesn't matter if the moment is right or not! Okay, well to a degree it matters, but the moment doesn't have to be absolutely perfect.
Think about a world where everyone just told people when they fell in love with each other. How much heartache would that save us? A lot! I mean yeah, sometimes it doesn't work out the way you thought it would, but it gives you closure so that you can move on. There would be a lot less "what if" scenarios... you would know how that other person felt about you and be able to get on with your damn life!
I'm just sayin, life would be easier...