Beauty is relative.. To you something/someone might be the most beautiful in the world, others might find that person/thing very bad looking or at least normal.
Beauty is in the eye of the beholder in the sense that, to you a beautiful person is a nice person, but to others, maybe, tey wouldn't care about how nice they are, they care only about how that person looks.
On the things/art side, if a person says something is ugly, you can't argue, since everyone has his/her own taste, for example, when modern at came out, some people didn't even consider it art, yet others fell in love with it!