He loves her. He knows that with every inch of his being. He can barely remember a time when he didn't. It's not a conscious choice, it's not even something that bothers him all the time, it's just a fact, it's just a part of him - Ignores the (very stupid) finale. Barney/Robin fluff, no sad feelings here!

Robin tells Barney about her weird dream where they divorce, he has a baby and she ends up with Ted. He tells her not to be so silly.