Called ugly by complete strangers, why?

I'm a black girl and I'm in my mid twenties now, I remembered a few years ago I used to be called ugly as sin by strangers that are the same race as me in places I go to shop at.. it happens now still but only a little.. what could be wrong with my appearance and what could cause these random strangers to say this to me? I honestly don't see anything wrong with me, I have a good body and normal face.. what's could be going on with me?
Called ugly by complete strangers, why?
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