A doppelganger is what we call someone who looks a lot like someone else, although the dictionary says it can also refer to someone with the same name.
I have noticed that I see doppelgangers everywhere. There are many people whom I meet who strike me as having a strong resemblance to someone else I know or, more likely, to a public figure whose image frequently appears in the media. It seems to be a personal quirk since other people don’t seem to see the resemblances that I see. When I am watching TV with friends and family and I say that someone on the screen looks like someone else whom we both know, very often they cannot see the resemblance at all.
The funny thing is that even though I often see doppelgangers of other people, I have never seen a doppelganger of myself. Perhaps we are reluctant to give up the idea that we are so distinctive that there is no one else who could be possibly like us. This may also explain why, when I tell someone that their looks remind me of someone well-known, they are always surprised and because they sometimes do not view it as a compliment, I have stopped telling people this.