The most profound my grandmother said, which I thought was pretty stupid when I was young, was:
"Everyone gets old, if they live long enough."
My mother also had some pretty good sayings.
"You'd get used to a wart on the end of your nose if you had it long enough."
or
"Every old crow thinks her little crow is the blackest."
(She was a 1st grade teacher and dealt with proud parents all the time.)