The Great Poet of Urdu Mr Galib has told -
"Umra bhar galib ye Bhool Karta Raha,
Dhool Chehre pe thi ,Aur Ayina Saaf Karta Raha."
Means-
"Entire life Galib has committed mistake,
Dust was their on his face only,but he went on cleaning the mirror".
Therefore we must have capacity to judge that we are at fault and not the others.