Perhaps more to the point, do you guys refrain from a glass of wine with a meal before traveling on holiday or deadheading, on the off chance that you might have to step up to the flight deck within the next 8 hours?
Surely when an off-duty professional pilot gets a phone call saying “we’re short of a pilot, can you fly today?” they make a grown-up assessment whether they’re fit and able to fly, and if not for any reason, they say “sorry, no, unable.”
I was looking at that question from another perspective. In light of recent and past events, what if a pilot becomes incapacitated and you could be an extra pair of professional hands to assist the remaining pilot (assuming a two crew FD of course)?