That is so romantic! How does an ENTP know this!?
I figured out recently that going through life living only by one's head was about the least logical way of going about things. I would be missing out on a huge chunk of the human experience if this were to be so.
It also came about in a seemingly weird way - through the study of hard science. We know these things exist, and that they're the result of neurochemical reactions within the brain. A great deal of evidence is also piling in on the function of pheromones in the human body. Another person's chemical makeup can be so harmonious with your pheromonic receptors that you literally do not know how you lived without their presence.
The biggest jump, however, was in the full internalization of the social nature of humans. A man is not meant to be alone, no matter how introverted his nature may be; we couldn't survive that way. Therefore, it follows that the greatest sense of contentment comes from fulfilling social impulses - love, essentially (Fe speaking here).
How does this relate to being an ENTP? Well, I guess the best way of explaining it is in the same way one explains music, alluded to earlier. Music is mathematics - the expression of a relationship between multiple compressional waves over a period of time. However, that only tells me the objective reality of it. The way the brain interprets these patterns are completely different from person to person, so that what is euphonous to one is cacophonous to another. So it is with human interaction.
On the surface, romance is nothing but the assemblage of behaviors in order to produce a desired result - sexual intercourse. That doesn't tell me about how romance is, however, just how it works. That's easy, old hat, and boring. The interesting part is the reaction that it engenders.
At these moments, my Ti function lights up to let me know that it's a rush of norepinephrine, serotonin and dopamine that is causing these effects - this allows me to have a bearing on the situation. This has usually derailed me in the past; nothing is less romantic than someone trying to think through romance. What I've been working on is letting the Ne take over in these situations - what do I do to follow the pattern. Fe jumps in and says "well, what would you want to have happen if you were in her position, having these sorts of restrictions and based on this information". Then, I just act upon it.
What learning about types has brought me is an understanding that others go through this process in a completely different way! Not only that, but combined with that group survival internalization, there's an understanding that this is good and necessary for human survival. None are better, none are worse.
So upon reflection of the whole thing, I ask myself - what is the greater pattern here? Is it the mere movement of brain chemicals? It's there, but a moot point to others. Is it the desire for sex? Of course, but that manifests itself completely differently in others. Is it the need for bonding? Yes! That's something everyone recognizes. How do people bond? They have their parents and siblings given to them, but how does it work for everyone else?
Then I looked within and found the answer. The people I truly love and care about each have an indelible aspect of their character etched upon my psyche. It would be impossible to even consider my life without their presence, while it's easy to replace the ones I merely like with someone of similar temperament. Likewise, it's my most fervent hope that they regard me in the same way.
It's similar to the concept of
karass that Vonnegut brought up in
Cat's Cradle - a group of people who for whatever reason are working together toward a similar purpose. I can't escape these people; it's almost as if the nature of the universe won't let me, much as the wavelengths represented by the notes C, E and G cannot help but make a harmonious chord.
I know that's a bit of an insufficient explanation, but it's all I can really express at this moment. It will take a bit more thinking to refine.
How exactly do you do that without being explicit? And how do you know just how much (not too much) increase in physical contact to apply? Wouldn't the increase in physical contact decrease the comfort level? 
I'll be lurking in this thread from now on for tips.
