“Vicarious” is not a strong enough word to describe the effect of mirror neurons.
Mirror neurons come close to running the show when it comes to empathy and, possibly, to morality as well: We respond to what engages us.
Demagogues dumb us down. People we admire inspire us to try harder. Encouragers rouse us; gloom-and-doomers deplete us.
Practice: Notice which encounters lift you up. Once you tune in, they are easy to identify.
Caution: You may discover you have people in your life you no longer want there.