Well as I doubt if I could get away with saying it's each time I lift when I fly.... I'd have to go with my check ride when I moved over to fly from Denham.
Heading back toward Denham, Q asked me to perform a wingover in the 22
To that point I'd always been taught to fly with accuracy and precision and apart from a few rapid entries and exits to/from confined areas, I hadn't done anything even vaguely aerobatic. I also had my reservations given the nature of the rotor head and it's -ve G activities.
Long story short... quite an experience and not something I'll forget in a hurry