Appendix:Snowclones/I'm an X, not a Y

Etymology
Star Trek, 1966-1969 and later, where the character Dr. McCoy tells Captain Kirk, "I'm a doctor, not a(n) [mechanic, engineer, etc.]" The first usage of the exact formula (similar ideas differently worded had previously appeared) was in the 1967 episode "The Devil in the Dark": "I'm a doctor, not a bricklayer." It was used again in four subsequent episodes of Star Trek (with other Ys), and further in the spinoff TV series and movies.

Statistics

 * Frequency: Very frequent (upward of 10 million |an+*+not+a|an+*%22&aq=f&aqi=m1&aql=&oq=&gs_rfai= Google results)

From the first two pages of Google results: "I'm an entertainer, not a fighter", "I'm an alcoholic, not a Barbie doll", "I'm an environmentalist, not a hippie", "I'm an anarchist not a capitalist", "I'm an anarchist not a Republican", "I'm an airplane mechanic, not a miracle worker", and "I'm an optimist, not a sap".