"Let none find fault with others;
let none see the omissions and commissions of others.
But let one see one's own acts,
done and undone."
- Dhammapada Verse 50
All too often we find ourselves consumed by what Mr. and Mrs. So and So are up to. We're quick to pass judgments, either thinking or talking about how we can't believe Mr. So and So does/didn't do this or how Mrs. So and So does/didn't do that.
Most often when we're judging others, we're either labelling them or their behavior as bad, wrong, or unwholesome. While we do so, we ourselves are unconsciously (and in so quite hypocritically) descending into unwholesome thoughts. These unwholesome thoughts lead to our own suffering through agitation/irritation, and if we're not being skillful and kind in our subsequent speech and actions, we then pass the suffering on to others.
And around and around and around we go.
As we continue our meditation practice, we find it more and more important to become aware of what our mind is full of, i.e. becoming mindful. Instead of being concerned with Mr. and Mrs. So and So, we become increasingly aware of what our mind is up to, how we're interpreting then reacting to the world around us. We become skillful in abandoning thoughts that lead to suffering, instead opting to cultivate and maintain thoughts that lead to happiness for ourselves and others.