Setting goals is always a good idea. Setting goals you can actually achieve is a better idea.
"I got my mark set at 2,000," Peterson said. "I've always had it at that mark since I stepped in the league, so that's where it's at. ... In order to accomplish great things, you have to set your bar high."
Peterson eclipsed that benchmark in 2012, becoming only the seventh running back to do so. The odds of him hitting that number at this stage of his career are slim.
Barry Sanders is the oldest 2,000-yard rusher, and he turned 29 ahead of that 1997 campaign. Peterson turned 34 in March. According to Pro Football Reference, John Riggins' 1,347 yards are the most in a single season for a player aged 34 or older.
Peterson's performance in 2018 doesn't point to a monster season on the horizon in 2019, either. He ran for 1,042 yards and averaged 4.2 yards per carry for Washington. For comparison, he averaged 6.0 yards per carry in 2012 en route to his historic year.
Setting lofty goals has helped Peterson become a seven-time Pro Bowler, and he'll likely be a Hall of Famer after he hangs up his cleats. In this case, he's headed for disappointment in the almost certain event he falls short of his objective for the upcoming season.