Kobe Bryant's career clock now has a hard expiration date. The five-time Lakers champ announced yesterday that this season would be his last. 

That's not too surprising, considering that he's in his 20th season and the final year of his contract with The Lakers. 

The surprise comes in the manner in which he announced it, through a poem titled "Dear Basketball," an ode to the sport and what it has meant to his life.

To better understand the psychology behind retiring, Take Two spoke to Ron Riggio, professor of leadership and organizational psychology at Claremont McKenna College. 

Press the blue play button above to hear more.