Some days, doing "the best we can" may still fall short of what we would like to be able to do, but life isn't perfect on any front-and doing what we can with what we have is the most we should expect of ourselves or anyone else.
Love isn't a perfect state of caring...
Very early in our children's lives we will be forced to realize that the "perfect" untroubled life we'd like for them is just a fantasy. In daily living, tears and fights and doing things we don't want to do are all part of our human ways of developing into adults.
Little by little we human beings are confronted with situations that give us more and more clues that we are not perfect.
What interests me so much about the characters of the Bible is that they make mistakes but God uses them anyway, in important ways. Nobody's perfect, but God can even use our imperfection.