Fame
Quickly, off the top of your head: Name the starting nose tackle for the Pittsburgh Steelers. Quickly! Come on, we're talking about a starter for one of the best-known teams in the most noteworthy football league in the world, so he must be famous enough for you to know his name, right? Right?
Okay, that was a trick question—the Steelers don't use a nose tackle in their base 4-3 defense. But the point remains that unless you're one of the three or four best players in one of the three or four most noteworthy positions on one of the three or four most popular teams in one of the three or four most densely-populated tri-state areas in the country, you won't become a household name.
Unless, of course you make a major blunder in a playoff game or on Monday Night Football, and that's not the kind of fame that you want. Ask Scott Norwood, if you can find him.
Even for the players who're never well-known outside of the die-hard fans of one team, the adjustment to losing this small degree of notoriety can be perilous. Within three years of retirement, more than one-third of former players claim financial hardship, and a similar number go through a divorce within six months of retirement.
In general, the players who've been the most successful after their playing careers end are the ones who don't let the fame go to their head, and who understand that the notoriety, large paychecks, and trays of pleasantly arrayed fresh fruits and cheeses are going to come to an end.
The NFL Players' Association and the NCAA jointly offer an internship program for current and former players to develop their professional skills and prepare for post-football careers. Some players use the internship opportunities to learn about college or professional coaching so they can stay involved in the sport, while others take positions completely outside of football in fields such as sales or marketing. Wonder of wonders, some of them even re-enter the fields they studied in college.