You define a good flight by negatives: you didn't get hijacked, you didn't crash, you didn't throw up, you weren't late, you weren't nauseated by the food. So you are grateful.

Summary

This quote suggests that one's perception of a good flight is often shaped by the absence of negative experiences. Instead of focusing on positive aspects like smooth flying or excellent service, the emphasis lies on what didn't go wrong - the absence of hijacks, crashes, vomiting, delays, or distasteful food. It highlights the tendency to appreciate and be thankful for a flight that meets basic expectations and avoids undesirable situations.