Seeing how a person conducts themself on a day to day basis will reveal their character. You get a feel for their moods, sense of humor, what important to them, where their boundaries are.
It’s only when a person is at the extremes of living — having a lot of power & influence, or in a crisis or under heavy stress — that you’ll see someone’s character. You find out what a person’s breaking point is when they’re under stress because you find out how much fortitude they have — a business man I used to know called it the IQ (for “I Quit”). You find a person’s level of integrity when they wield power because at that point that can do anything. What they choose to do with that freedom will tell a lot.