Bruce Lee say that "I fear not the man who has practiced 10000 kicks once, but I fear the man who has practiced one kick 10000 times". That means it doesn't matter how many things you know, it only matter's how much perfect you are with what you know.
In our life we can forgive the person who hurt us wantedly but the one person who we can't forgive is the one who laughs at seeing while they hurt us(especially our friends)