In several of my books I've talked about the neurological reasons for this. It's just the way we are, the way our brains and bodies work. No use fussing about it, but it's good to recognize when it's getting out of hand. Nevertheless, Love is Freeing It may sound like a paradox after the last point, but love always invites freedom. It always points toward increasing freedom for both lover and beloved, encouraging them to be who they really are.
Love always wants to become more unconditional and unconditioned.
We can and do grow in love, and in freedom for love. In the Judeo-Christian tradition, this means increasing fulfillment of the two great commandments. I think of Anthony deMello saying that early in his life he wanted to be a holy man. Then in mid-journey he wanted to be a loving man. Finally, he said he wanted to be a free man.