This happens to me from time to time - I'll be having a 'ugly day' and really, nothing my darling man can say to me makes any difference, because I know he loves me, and is entirely subjective and biased. Your partner probably means everything he says, because in his eyes, you're gorgeous, all the time. No matter what you're looking like (first thing in the morning, panda eyes, in your trackpants, always) !!!
Having a compliment coming from a stranger is a more objective statement, because they don't know you, they don't know what a beautiful person you are...all they know is that you LOOK beautiful. It is more convincing when you're feeling down.
However, it's nice to know that to one person at least, you're always beautiful
