I've thought about this question many times. I'm a complete romantic and I always wonder what it is about this love thing that is so beautiful.
One of the many conclusions I have arrived at is that love helps you take the focus off yourself. You do things for someone else, your happiness lies in the other person's happiness to a great extent and it keeps your mind focussed on something other than just your own needs.
I've often reflected on the highs in my life (love is one such high) and observed that when I have lost myself, when I've almost forgotten the 'I' existed and just enjoyed the moment, those highs have just happened.
Does anyone else feel that way too?