The experience is always temporary. That’s because falling in love is slightly illusory, for you only see the good qualities of the other person and none of the minor points. After a while you start to see faults in your beloved. It also becomes clear that you are not really one, but you both have your own desires and wishes. You want sex and he doesn’t or you want to go out while she wants to stay home.

When the butterflies are gone the relationship might end, but you may also start to appreciate your lover as he or she really is, longing for a bond that will last. But it will only work out if you both learn how to compromise and walk the extra mile. The chance that it will develop into a long term loving relationship increases:
if you have similar backgrounds and similar beliefs about various issues.
if you share the same interests and hopes for the future.
if you have established a balance between giving and taking: giving to each other equally.