FreedomQuotes: “If you’re not catching flak you’re not over the target”The history of the self-congratulatory cliche suggests that this origin myth is bollocks.
This apparently originated from WWII bomber pilots.
They could tell when they were over the target
when they could see, hear and feel the flak.
I'm going to be all radical and contrarian and counter-intuitive here, with the suggestions that
(a) if you're catching flak it's because you strayed within range of an anti-aircraft battery; and
(b) if people are laughing at you, it's because you said something stupid.