I guess this means they fired me. I'll never make the mistake of being 70 years old again.
Source, in full
On being fired by the Yankees after the 1960 World Series; as quoted in Casey; the life and legend of Charles Dillon Stengel (1967) by Joseph Durso; reproduced in "'Casey': A Career in Stengelese" by Ed Rumill, in The Christian Science Monitor (April 19, 1967), p. 13