A Cat who had 21 Years of a Very Good Life is a very fortunate Cat indeed.
It must be very difficult not seeing Stuie , as after 21 yeras you would be so used of seeing and loving your Companion.
Stuies an Angel now, and while hes very happy, he will drop in on you and see how you are doing, until you are reunited with Stuie at The Rainbow Bridge.
One Fine Day.