Schadenfreude is "enjoyment obtained from the troubles of others" (according to my trusty Merriam-Webster's Collegiate Dictionary).
Schadenfreude is what a top golfer might experience, after playing the circuit for twenty years and remaining morally and ethically pure as the driven snow, when he sees a celebrity golfer finally suffer humiliating exposure after years of behaving badly.
Old retired George could feel schadenfreude when his next-door neighbor slips and sprains his ankle on a patch of ice by the neighbor's own front door. After all, the neighbor reported George to the city for not shoveling a wide enough path on the snow-covered sidewalk in front of George's house.
And it's just possible that the guy in the Porsche who rode Amy Lou's bumper for three blocks until he could race past and beat her to the red light will be the cause of her schadenfreude when she sees him pulled over by a patrol car a block later.
I'd like to pretend I never enjoy someone's mishaps or misfortunes, but I definitely smirk when I see some jerky driver pulled over by the cops. And I've been known to feel a bit smug when someone who fiercely defended his point of view against all my arguments is proven wrong and he suffers some minor inconvenience as a result.
Whether we're writing fiction or memoir, schadenfreude is a great topic to explore as we develop our characters. The cause of the emotion and the degree of joy and gloating that follow might tell us much about the character's sense of right and wrong.