Sometimes my boyfriend will ask my opinion about him, one of his qualities, something he does, etc. It usually comes up as part of the conversation. I always answer truthfully and along the lines of that he's great, wonderful or the best guy I've ever dated. He always says that he doesn't see himself that way, but is glad that I do. He compliments me on his own, but acts as though I should already know it or am silly to question it.

He did say once that his exes gave similar compliments as me. So, why is he feeling insecure? Is there any way I could reassure him so he doesn't feel/think that way?