Because we're like birds - we need to fly. Love gives people wings, but sometimes you choose the ones made of wax. Get too high - they will melt. You can see love as the greatest feeling on Earth. You can see love as an illusion. You can see it just like business - I was quite angry once and wrote a comparison of love and simple sales contract, though you might disagree with the approach completely.
It doesn't matter how you see it, it exists somewhere. At least most of the people say so. And one would do anything for those few moments spent flying.