I hate to be cynical, but reality is that the permanence of any musician's retirement often depends on how good they are at managing their lifestyle vs. their available retirement funds.
 
Which can be difficult if they have never really had to learn how to live on a budget.
 
I remember an interview with Pete Townshend from (I think) the 1980's where he talked about one day being dead broke and then the next day a royalty check would arrive...

drewfx1
I remember an interview with Pete Townshend from (I think) the 1980's where he talked about one day being dead broke and then the next day a royalty check would arrive...

 
Wow, I'm in that exact same position! Just without the royalty check... 
 
All I can say, is when your tour promoters are Depends and Ensure, it's probably time to stop touring. 

I saw the Who on their first, last tour, and it was around '85. I never thought farewell tours could become an entire career path until those guys started it.

As I've told before...  I had tickets to see the Who, but Entwhistle passed the night before the concert so I never got to see them...