Be proud of character
Principle 6 from the Enchiridion
If you want something to be proud of, look at the way you choose and behave. Possessions and advantages can disappear.
Original Passage
Don't be prideful with any excellence that is not your own. If a horse should be prideful and say, "I am handsome," it would be supportable. But when you are prideful, and say, "I have a handsome horse," know that you are proud of what is, in fact, only the good of the horse. What, then, is your own? Only your reaction to the appearances of things. Thus, when you behave conformably to nature in reaction to how things appear, you will be proud with reason; for you will take pride in some good of your own.
Modern Interpretation
It is easy to build an identity around work, status, connections, or the things we own. Epictetus points out all of these can change. They are not the same as our character.
What sits closer to our control is how we choose and act. If you want something to be proud of, look at whether you were honest, fair, and able to govern yourself. That measure is less fragile than one built on what you happen to have.
In Practice
A colleague buys an expensive car, and suddenly you are comparing your whole life with theirs. Before that comparison runs away with you, ask what you are actually measuring.
The car may be lovely. It still tells you very little about whether either of you is living well. Bring the measure back to your own choices and conduct.
Reflection Question
What have you been using to measure your worth lately: what you have, or how you behave?