The Decision to Croak.

[Boromir88]

Sorry for the bad title, I just like the word "croak." Anyway, I want to know the significance (if there is any) in Tolkien's characters just deciding to croak? What I mean is, there are characters (that I will get to in a minute) that I guess feel their lives are fulfilled and just decide, "Ok it's time to kick over."

For instance, Aragorn takes the Numenorean "right" in deciding when to die, so he croaks on March 1st 1541.

Then Arwen all depressed goes to Lorien and croaks.

Merry and Pippin go to their respective Kingdoms that they served and spend their last months there and croak.

Sam after his time as mayor is done goes to Aman. Sam at the time I think was approaching 100, which means Frodo (if still alive and I assume so) was around 110. Meaning they would probably croak soon.

So, what's with Tolkien's characters travelling to a place, and then shortly croaking? Have they reached fulfillment in their lives and so they go to their own special place of rest (like Merry to Rohan, Pippin to Gondor, Arwen to Lorien) then shortly after just decide to croak, since they have fulfilled their life? What's the special significance/theme behind this (if there is any that is)? Just seems too coincidental that Tolkien has all these characters go to their own place that means something special to them and soon decide to kick the bucket.