Be tolerant with others and strict with yourself.
Marcus, despite being emperor, constantly held himself to a higher standard than those around him. He witnessed the flaws of senators, generals, and even family members — yet chose to meet them with compassion. But when he erred, he didn't offer excuses. He expected himself to lead by example. This wasn't self-punishment, but self-mastery. He believed real leadership comes from holding your own behaviours accountable while forgiving the shortcomings of others.
Hold yourself to your highest standard, and others with gentle understanding.
"Let he who is without sin cast the first stone."