Soul Mates vs. First love

Would you kill for the one you love, or would you die to protect them? Today, people confuse they're first love's with the term "soul mate". Personally, I believe that the first relationship that one has is doomed  to fail. Another person (an optimist) might say that love might fizzle out, and that in they beginning it was love, during the middle it was good, but at the end the love faded away.