You see other people’s flaws in high definition and your own in low resolution.

Other people’s habits are observed, and your own are experienced from the inside, where the edges blur. You notice every time a friend interrupts and almost none of the times you do, because yours come attached to a reason and theirs simply arrive. The difference is not in the behaviour. It is in the viewing angle.

Pick one thing that irritates you about somebody close to you and count your own version of it for three days. Just count, without judging. The number is usually surprising, and knowing it changes how the irritation feels.