Well!
You want to know why you can't just enjoy what Erica Jong called the "zipless fuc*"...
That's to say, two strangers enjoying a sexual encounter that is seemingly free of all remorse and guilt. It is absolutely pure, there is no power game and it is free of ulterior motives. It's just casual, meaningless sex for the pure pleasure of having sex.
Actually, I'm sure that that happens all the time. But only to a select few. I believe that ALL people eventually seek a connection with another person, preferably a person that they Love or feel a very strong connection to. I don't think that that's something that is learned or only acquired through experience. I think it's something that's built-in to every human being. Even though there are people that can put that need on hold for some period of time, sometimes for several years, that biological need for closeness, intimacy, Love and connection is too strong to ignore. We ALL want to Love and BE Loved in return. It's one of the universal attributes of the human species. Sex without experiencing the connection of intimacy and Love is empty. It may feel good physically for a short period of time, but it leaves you feeling unsatisfied, unfulfilled and uneasy... You come away from the experience feeling like you missed out on something important. You want to feel something more, but don't quite know what that something is. Something feels unfinished and you yearn for whatever that thing is that will leave your heart feeling complete and at peace.

Indeed. That something that is missing when you have meaningless sex with someone is the magnificient connection you experience when you are intimate with someone you Love, trust and respect and who gives Love, trust and respect in return.

THAT'S why you can't seperate sexual feelings from Love and intimacy.