As we entered the 2011 tennis season, all eyes were on Rafael Nadal. The then world No. 1 had captured the past three major titles, and would have his sights set on the "Rafa Slam" as the year's first Grand Slam tournament, the Australian Open in Melbourne, kicked off.
Despite being a considerable favorite entering the tournament, an ailing Nadal was bounced in the quarterfinals by compatriot David Ferrer in three routine sets.
By the time the 128 player field had been whittled down to two, neither Nadal nor Swiss rival Roger Federer were in the final for the first time in 11 Grand Slams.
From then on, Djokovic won nine titles, including five Masters 1000 shields and two of the remaining three majors, excluding the French Open. He finished the year having taken over the No. 1 ranking spot and with an outstanding 70-6 win-loss record.
After capturing two more titles to start 2012, defending his crowns in Australia and then in Miami, Djokovic had inherited the title of most followed tennis player on earth from Nadal.
With the clay-court season, the Spaniard's best, just about to start, it was clear that if Djokovic could continue his head-to-head dominance over Nadal (seven consecutive wins), he would be considered one of the all-time greats and the clear alpha-dog of today's game.
Just about 17 months after Rafa's failing Down Under, Djokovic was only seven wins away from completing the "Nole Slam."
Having already lost matches at Indian Wells (John Isner) and Dubai (Andy Murray), the "Djoker" was not tipped to unseat Nadal as the "King of Clay" quite yet.
Djokovic was defeated by Nadal in Monte-Carlo, countryman Janko Tipsarevic in Madrid, and once again by Rafa in Rome—Djokovic's stronghold on the rest of the tennis world seemed to slowly be weakening.
Djokovic then advanced to the Roland Garros final for the first time in his career, but not without surviving back-to-back scares early in the tournament.
He fought off a two-sets-to-love deficit against Andreas Seppi in the fourth round and staved off four match points to defeat Jo-Wilfried Tsonga in the quarterfinals.
Although Djokovic was still winning, there were definitely holes in his game that even lesser players could pick out.
Djokovic would go on to lose the final—and see his 27-match winning streak in Grand Slams end—once again to nemesis Nadal, who won his seventh Roland Garros crown.
When the world No. 2, the consensus favorite for Wimbledon, was shockingly bounced by 100th ranked Lukas Rosol in the second round, the "Djoker" then became the clear favorite to win a second successive title at the All-England Club.
After a relatively smooth run to the semifinals, Novak faced off against world No. 3 Roger Federer, a player he had defeated in seven of their past eight meetings, including just a few weeks ago in Paris, where Djokovic handed Federer a straight-sets loss.
Instead, the Serb's greatly acclaimed footwork undid him, as he ran apathetically and slipped about the green grass. Federer, arguably the all-time greatest player, but still five year's Djokovic's senior, dominated the tempo of the game, ending Nole's hope in a four-set win.
Who Will Win the 2012 US Open?
Djokovic, who last year at this point had lost only one match, has already lost seven, more than he did all of last season.
Exactly 52 weeks after claiming the World No. 1 spot from Nadal, he has lost it to Federer, who went on to claim a seventh Wimbledon triumph.
Djokovic has still had a great start to the season, but this is not the Novak that we know from 2011.
What has changed?
The simple answer is that no one can maintain that high a level of anything for so long. What Djokovic pulled off in 2011 is simply put, one of the greatest seasons in any sport.
Playing in an era with two of the sports all-time greats and other super-talented players, Djokovic went an entire season losing only six matches.
Even late in 2011, during an indoor where Djokovic suffered three of those losses, not counting his withdrawal against Tsonga in Paris, we started to see the tremendous amount of spent energy catch up to Djokovic.
He already looked tired then, and by becoming a superstar around the world, life is only getting more exhausting for the current world No.2.
During the offseason, all of the top pros knew who the man to beat was. Djokovic. Most of them, especially Nadal, probably studied the Serb's game so intensely in order to discover a formula to defeat him.
Djokovic's willingness to slide on hard-courts was a big part of his success last season. He would get to balls that should be impossible to touch, and get them not only back in the court, but deep, making it tougher for opponent's to adjust.
The wear-and-tear of all that sliding has definitely showed more this year, with players needing to hit only two should-be winners instead of five to take just one point off the Serb.
Other parts of his game have slightly deteriorated, such as the fact that he's missing more rally shots, a rarity in a game last year.
The pressure of being so recognized probably also carried him out of the zone that he was in for so much of last year. Maybe this "slow" start will relax him and push him to prove critics that think 2011 was a fluke.
Maybe he'll start working out as hard as he did between 2010 and 2011, motivated by his ranking drop and prove that he does belong at world No. 1.
The worse-than-anticipated start should have been expected. Novak Djokovic shouldered so many expectations entering the year, as many people projected him not only to complete the "Nole Slam," but also a career Grand Slam.
Djokovic is still playing well, and it should only be a matter of time before he rediscovers a little more 2011 magic.