This is kind of toxic and wrong and is the kind of thinking that leads to Hollywood style short intense relationships that don't last because people keep looking for mr/mrs perfect who they can find no wrong with.
You should absolutely not love a person's flaws or love their sad or angry versions. You should accept them. There's a big difference. You should recognize their strengths and weaknesses and love the person for who they are sure but there's a clear distinction where on one side you're partners, whole complete people who are both bad and good, on the other you're some impossible ideal that when reality sets in will crumble and the relationship will die.