Genuine - and I guess one-off - "newbie putdown" I heard in SOAF from an old-and-bold ex-RCAF, ex-RAF and then SOAF guy:
"I've been in more Air Forces than you've been on Squadrons!"
An another one really from a 1369 (not sure about some of the well-known if apochryphal ones earlier):
"This officer will never set the World on fire, but will be the first to help you put it out when someone else does!"