Why do people have to get heartbroken??? =/?

I know it's a stupid question, because heartbreak, pain, and rejection is part of life. I'm not really talking about the kind of heartbroken where you like a guy and he doesn't like you back. I'm wondering why people have to go through the whole first love thing. The feelings are so intense for that person, and you want it to never end, yet somehow it almost always does? But, really, why? I'm still with my first love right now, and have been for a year, and I have never felt so strongly for a person before, yet I know since I am young and after all, this is just a first love, that it will end, but I don't want to be heartbroken again. Why do people have to go through heartbreak and how can you lessen the blow?