A second point is that we, as aviators, quickly respond to the blinking red light and the honking horn but we can miss the cues when things are failing but doing so only gradually. And when you add reinforcement from other sources such as no one missing the approach, no one going around, no one having problems clearing the runway after landing, no reports of braking problems, one would have to be somewhat psychic to conclude that the day is anything other than just another day at the office.