The only thing that kept me from flying a sortie was the runs. Especially during an upgrade. And especially if it was an air to air sortie. But then, I'd always be a little more "gentle" if I wasn't feeling well. Funny thing was, as soon as the canopy went down I usually forgot all about not feeling well.
Just glad I never GLOC'd.
It was a Navy guy that told me you should always ask yourself before flying, "Can I fart with confidence?"