For me it's obvious why the heart is depicted as the center for love. It's here, in the chest where I feel a great wave, a rush of feeling when a moment pulls the curtains away and shows me the love I feel for someone/thing. It's as if my torso decided to remind me that it is still there and serves a function beyond physiology. I swell up and get filled with wonder, awe, amazement, happiness and sadness all at once. The sadness comes at the end when I realize that this is a moment and that I will soon forget to be in it and will likely revert back to the way I was before, in love but with the curtains drawn.
Ah yes, but is not love in itself a physiological concept? What more is it then a primal drive to reproduce? Evolution deemed the feeling of "magic" that goes with love brought people to continue their species better, so now it's found in nearly all of us. But, I'm not a personified image of evolution or biology. I am a human, and damn do the butterflied and buzzing in my chest feel exactly like what you describe. The complexity of being in love is vast. You overthink and you stumble and you get nervous, yet every moment feels like pure magic. It's impressive, but it's no surprise so much art is based off of love. After all, what more is art than an expression of our humanity? When one of, if not, our biggest drives as humans is "love", of course that's going to manifest itself in our art. Even the negative parts feel almost.. inexplicable. Indecipherable. Surreal. I'll sometimes think during the holiday season, "man I wish I had someone to be with next to this fire"
or when I'm under the stars I might say out loud to my only company, the open field "if only I had someone else to share this view with". What does that mean though? Is it magic? Sure as hell feels that way. More interestingly though, is the underlying psychology (or, specifically, applied biology) of love. The one that gets me the most is a phenomenon that's always prevalent. Humans are social creatures and being social is rewarded. That cute confident girl who can be friends with anyone? She'll subconsciously force her way into everyone's heart. When you see someone so happy, so confident, your brain comes up with subtle excuses. "Oh, we have x and y in common. We're perfect" but in reality that's just confirmation bias your brain produces after it's set it's mark on the 'evolutionarily perfect match'. etc. etc. and so on. What's my point? How much of love is logical? Not very much. I don't know, maybe I'm just a bit resentful since I'm fairly timid.
No, you are on to something here. Love is not logical, if it were we would only pair up with people that complimented our weaknesses but many people end up with people like themselves that exacerbate their shortcomings. Logic plays no part, in fact I would reckon that for the most part it is convenience that plays the greatest role.