I LIKE the part about maintaining.........,
I had perfect, or absolute pitch all my productive years, and never failed, when healthy and acute. I pitched performing groups with it by mouth many times, and set pitch on a single instrument, for others to tune to..
But NOW, I am elderly, and never use it; I miss about a third of the time when attempting just "out of the blue", and am more easily misled by noise in the area...Perhaps it indeed, does require a certain maintenance...!!!
My Regards, John Cont