When someone makes a statement implying that they revolve around you (your the center of their universe) it means, metaphorically, that you are the sun (the strongest gravitational pull around and in control) and they are the planets (and subsequently weaker, submissive and at your will). In this context its quite odd that someone would give up control of their entire being to another human. Unless its for the purposes of role play or a particular lifestyle. We aren't talking about that though.
In cases like these the one speaking these ridiculous pick up lines is clearly smitten at an unusual level. The relationship can never be equal when it begins with one person having near total control. So when the smitten person realizes the other is mere flesh and blood and not a god the struggle to take back self-control will most likely follow. This is just one angle to this, there are more.
If you look at planets that revolve around a sun there are many, some closer than others. While one side is warm and bright the other is dark and cold. Which translates to the sun can never bring life to all of a planet, it must do it in sections. One side will must suffer and concede to another.
If you relate that to dynamic human emotions we have a recipe for a very unhealthy relationship.
I can't speak for anyone else, but as for me, if I find a "planet" orbiting within my gravitational pull...I'm going to consume it for more energy and when I'm done the planet will not survive.
Still want to make me the "center of your universe?"