Originally
Very simple:
Since my talent is not likely to change after 55 yrs of playing, I prefer to apply it to several keyboards for my own satisfaction, and provide variety for my audience.
Reminds me of the song Ricky Nelson sang Garden Party with the lyrics “can’t please everyone so ya got to please yourself.” Good point too about talent not improving after 55 years, same for me but it’s more like 45 years.