"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." (Epictetus, Enchiridion 6)
"Be not a busy-body in other men's affairs" is a mantra I heard frequently in my younger years, and for good reason, namely that other people's business was simply that--their business. Don't be nosy. Let your thoughts and feelings be genuine, your own. Be aware of how you think or feel and make certain you have not assumed the thoughts, feeling, even the experience of someone else, as your own. In short, it's rude, arrogant, prideful.
Maintain control and support others by allowing them to display their own excellence, anger, frustration, joy without becoming an uninvited champion of a cause that is not your own. If they call you to celebrate with them, then do that. If they call for support during a tough time, then do that: empathize, sympathize, but don't plagiarize.
