We take some things to heart in ways that aren't helpful. Criticism—especially when mean-spirited—can crush our heart and break our spirit. Whether accurate or not, criticisms tend to play like a never-ending tape in our mind.
Flattery taken to heart is a trap. It's self-deluding and sets us up to fall when we crash into reality. Like someone who can't carry a tune trying out on the American Idol stage because family or friends tell them they sing well.