...when you're being advised by ATC that the runway is wet and you feel compelled to go around to find a suitable alternate - because the wet braking action on helicopter skids is so terribly unpredictable!
...when ATC advises you that "Der is a bad activity on de endi of runniway 05"
It only dawns on you that "bad activity" on the runway must've meant something other than traffic congestion of 1 airplane or more after flaring into this huge flock of exotic poultry...
... when you ask the controller something out of the ordinary like "How old is your grandmother?" and are subsequently cleared to join the left downwind
... when your contracted mechanic on his way to fetch a coffee is stopped at security and subsequently interrogated for 30 minutes for wearing a visitors badge while a few days later your passengers suddenly turn up at the airside without even having a ticket yet.