Geography Of A Man

Geography of a Man
 
A guy's life can be described as a train on a railway track.
 
When they are 20,
 Every station they want to stop.
 
 When they are 30,
 They can only stop at one station.
 
 When they are 40,
 They want to stop but they are not allowed to stop.
 
 When they are 50,
 They want to stop but they cannot stop.
 
 When they are 60,
 They can't even start. How to stop?