I like this explanation too. It also fits with my thinking that when you think someone looks just like someone else, ask another person and they can't see it.

I like this explanation too. It also fits with my thinking that when you think someone looks just like someone else, ask another person and they can't see it. I believe this is down to the way our brain recognises matching features against the stored 'standard face' of an person, but other people don't match in the same way as their 'standard face' is different.