Benevolence is lost so easily

Almost a year ago I had an accident that would subsequently cause a six month depression and keep me from walking for three months. At first I needed a wheel chair to leave the house. When my boyfriend reluctantly made the drive to see me on the weekends he would complain that putting my wheel chair in his trunk would mean he couldn’t put the top down on his convertible BMW.

This event has, whether completely justified or not, permanently shaped my opinion of his character and the character of every cock that drives a BMW.

So my question is this:

Why does the truth only show during our worst moments and our character shaped more by our own evils than graces?