If I think back to my high school boyfriend, whom I was with for nearly four years, I couldn't say I still love him. Thirty-five years have passed. When I think of him, I have some memories but I know I wouldn't feel that romantic love again if I ran into him tomorrow.
I look at it this way, people forge a path to my heart, or what I imagine as a deep pool of love I have inside me. Some people find a place very deep inside that pool, some just splash around on the shore. I get close to some, not so close to others. Love is at the center, always there. But love isn't enough to sustain a relationship and keep it healthy. So many other things come into play. We can lose our loved ones if they move away or die. The ones we love might make choices that we can't live with. We can love people who are totally wrong for us.
So, for those relationships of which I must let go, the paths they forged don't go away, but become overgrown with weeds and thick bushes. The path is still there but I can't see it anymore. Eventually it is forgotten, or so distant that it doesn't bring up any feelings anymore. That's not a bad thing. It just is.
No one can say how poly people love versus how mono people love. Everyone is different and unique. You find the ways to express your love that feels most comfortable for you, and create your life to support that expression. The rest -- definitions, labels, rules, structures, politics, problems, questions -- are just part of an intellectual exercise.