Funny, but that's probably one of the top most difficult questions for me to answer. One of the reasons it's difficult is that there are so many degrees of "love" as far as western culture is concerned. You can "love" a spouse or partner, a parent, child or relative, a friend, a pet, a place, a thing, an idea, etc.
For loving a person, perhaps you know how much you love them after you've lost them and not fully until then.
"Don't it always seem to go that you don't know what you got 'til it's gone."
Same q