Believe in the good that exists in all human beings. Never assume you know the way someone will react to a situation or believe that you understand a person enough to make assumptions about their future choices or decisions. Negativity can only make a situation worse (and if I say, "an already bad situation worse", then I'm being negative).
My Dad always says, "When you assume, you make an Ass out of You and Me", and that's exactly the way I felt last night. I assumed something about one of my tenants and it turned out to be the total opposite. When I realized how much I had been thinking negatively about the situation, I felt grateful for the opportunity to realize my mistake.