[eljeffster]

This is a great song for this (in German):

This is the official video

Here is the same song where someone did a fairly decent translation in the video

Best lines of the song

man is nich so als wie man sich fühlt, sondern so alt wie man alt is.

one is not as they feel, they're as old as they're old

Mach dir keine Sorgen . . . deine Tochter Petra plötzlich Lara nennst

Don't be worried . . . [when] your daughter Petra is suddenly Lara

(talking about the effects of getting old- alzheimer's)