The 2011-2012 season did not end as expected for Kobe Bryant. He tore his achillies tendon on the final week of the season. The Lakers were playing to get the number seven seed at that point.
The Lakers winded up winning the game and went on to face the Spurs during the playoffs. They lost that series 4-0. People are skeptical that Kobe could come back from that kind of injury and perform the way he usually does. Bryant has played through many though injuries throughout his hall of fame career.
In October, Kobe hinted that he might retire after his contract runs out with the Lakers. Looks like the injury made him re-think a little. In an interview in Brazil with Glenda Carqueijo, Kobe said, "I could easily see myself playing another three or four years."
Maybe the injury was a blessing in disguise. Kobe possibly wants to pass his mentor MJ in rings. That's another reason why I think he said he wants to play another 3 to 4 years.