How does A define beauty in Every Day?

As someone who moves through life in a different body every day, A has a number of thoughts on beauty and attractiveness.
One thing A believes about beauty is that it's best when it's distant. This is because your memory can fool you into thinking things were better than they were. He also believes that if your beauty is unquestioned, other things also escape notice. It's easier to get away with things if you're attractive.
A also believes that people are more attractive in the eyes of a person who loves them. It changes the way someone looks at a person. A is unsurprised when he sees a boy that his host is in love with as unremarkable, because it's a lesson he's learned over and over.
A thinks at one point that sad beauty is a myth. He thinks sadness makes people unattractive, not attractive.