My theory for the thing we all, as humans, look for was the following:
An experience of consciousness that engages us on all the levels. This means that the most engaging experience would be an experience involving the five senses, the mind, emotions, and engages others with us.
Sex includes all these elements and it is maybe the most engaging and intense thing we can ever do.
Yesterday, I had a really engaging experience with my friends from the company I used to work for. There was no sex, don't worry:)