Real Life can be much more interesting than fiction. With over 500 episodes, The Simpsons have used a lot of ideas. So many reality is starting to copy them...
Don Mattingly's hair.
The recording of the 17th episode of the 3rd season of The Simpsons was a difficult process, requiring the 9 baseball playing guest-stars to record their parts whenever their respective teams where in town and last minute re-writes to meet the players needs. The plot was about C Montgomery Burns getting ringers for his baseball team, but them all being unable to play due to illness or injury except Don Mattingly. Don Mattingly was stopped from playing because Burns hated sideburns, telling Mattingly to cut his or he was off the team. A sideburnless Mattingly complied as best he could, but Burn still complained about them and cut him.
On 15 August 1991, a month after he recorded his part Mattingly, was benched because the Yankees decided that his hair was too shaggy and fined him $250 and $100 for each day his hair remained uncut. By the time The Simpsons episode aired, in February 1992, the episode seem to be parodying the situation, when it had predicted it.