New Delhi, May 18 -- An ancient Persian saying about two soot-covered pots has survived centuries because the human habit it describes has not changed at all.

There is a moment most people will recognise. Someone points out a colleague's mistake in a meeting while quietly ignoring their own. A friend complains about another person's bad habit, one they share themselves. A family argument erupts with blame moving in every direction and accountability in none. The tendency to see faults clearly in others while remaining blind to the same faults in oneself is one of the oldest and most documented patterns in human behaviour. A Persian proverb captures it with striking economy.

The saying, direct in its imagery, goes: "The pot says to the p...