Not every boarding pass gets us on a plane.  We take for granted that a rectangular piece of paper with an airline logo printed in the corner allows us to board.  What assumptions once re-examined might be transformative?  How often do we pause in the middle of everyday activities to consider all that operate smoothly for us to advance without complication?  One warning light can delay a flight for hours, even when the non-cooperating part appears to be less than vital.  What is essential for your journey?  Who have we taken for granted?