Short one on Love and Sex

Love is the best driving force that a human has. So is hate. But isn't hate just a form of love? 

Sex is a biological need, understood. But sex combined with strong emotional content takes you beyond the normal level of consciousness
And once u achieve that , u never want to do the sex without the emotions! Because you transcend, transcend into a new world of pure union, a oneness that isn't selfish or fun but is selfless bliss.

P.S. I'm just a non-believer of casual relationships, not against it.
How can a full human and a bond with the human be taken for fun or for granted?