A negative way of seeing people and things has nothing to do with reality. Aveiros (sins) as a youth cause massive guilt and negatively influence our perception (of ourselves and others). Every Jew should strive to be a good guest. We do not always appreciate the goodness that others do for us. Every little bit of agmas nefesh (aggravation) is an opportunity Hashem gives us to overcome this middah (character defect). When we strengthen ourselves to see good in everything, it has an unbelievable influence on one's family. We should always feel all the tov (good) that Hashem sends us at all times.