None of the descriptions in classic literature make any sense to me at all, so I thought I'd try Hubski. Please answer if you're in love, whether it's new or old, happy or chaotic, gay or straight, long distance or living together...
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.