It’s clear when you read about Cato and Marcus Aurelius that these were men of great reserve. Antoninus, too. They were friendly and kind of course, and to people who knew them well, there was frivolity and fun, but they kept something back from strangers.

They were self-contained.

This was a rare thing in Rome and it’s a rare thing today. We are surrounded by over-sharers and gossip mongers. People celebrate being hot messes, not just getting up in your business but getting you up in theirs. We have busy bodies and energy vampires, trolls, and toxic narcissists. Nobody thinks before they say things. Nobody holds back. Social media has created an epidemic of poor boundaries, which in turn has created a culture full of people with poor self-image, low self-esteem, and very little sense for where other people end and they begin.

The advent of a new year is the perfect time to commit to having better boundaries in your life. Boundaries between work and your personal life. Boundaries between you and people in your life. To draw some healthy borders between what you’ll share and what you won’t, what you’ll accept and what you won’t, how you treat others and how you expect to be treated, what is your responsibility and what isn’t. As Jay-Z explained once, particularly in regard to adjusting to his success and fame, “It’s about knowing who you are, and just doing what’s comfortable for you, and not letting people pull you in a thousand different directions. Because if you allow [it] . . . people will have you doing all kinds of stuff, but it has to make sense for you.”

The Stoics talked about knowing your place and path in life. They talked about tuning out gossip, about keeping your distance from flawed people, about not picking up bad habits from others, about reserve and dignity and poise, about not caring what others think.

This is difficult stuff. It takes a lot of self-discipline. But it is a key to health, happiness and in the case of Marcus and Cato and Antoninus, greatness too.