Maybe I don't understand exactly what I'm supposed to be listening for, or maybe my ears are bad, but I don't think I can hear the missing fundamental unless it

Maybe I don't understand exactly what I'm supposed to be listening for, or maybe my ears are bad, but I don't think I can hear the missing fundamental unless it's actually being played. I also don't quite follow how arbitrary harmonics can result in a specific note--is the idea that if you conjoin any 2 or more harmonics of Note X, their pitch will sound like the pitch of Note X even though it is not technically being played?