LOL, I'm about to graduate college but I also see that kind of thing a lot still. I have a friend (more of an acquaintance, were aren't that close) who a few weeks ago got into a relationship with a girl and the two are now constantly professing undying love for each other. Makes me want to gag
Love is a pretty nebulous concept that is hard to explain. I am very young for sure, but I have been in a relationship for half a decade now and I think I have learned a little from it. It's a lot different then infatuation and 'puppy' love, that's for sure. Early in a relationship, during that honeymoon faze, it's like a flame. It's all lovey-dovey, like a chick-flic romance or Backstreet Boys love songs type of thing.
Mature love is a lot different though. It's like two trees, they were once separate but after a long time, through growth and change, their roots become intertwined. From above the ground it looks like two separate trees. However, from under ground we can see that they have become so intertwined they cannot be separated, one cannot live without the other. In removing one you kill both trees. At the end of the day it isn't about hearts and flowers anymore (though romance always has it's place), it's about looking into their eyes and realizing that they are your best friend, a friend that is truly and deeply a part of you. Two parts of one greater whole.