A student was walking behind Rabbi Ishmael ben Yose. Another student was walking behind Rabbi Hamnana. Both students were following their teachers closely, learning by watching.
They saw the same thing on the same day. Each teacher, in the middle of an ordinary moment — walking down an ordinary road — suddenly showed fear. Not a reaction to a visible threat. No robbers, no wild animals. A sudden, inward afeared-ness that came over them both.
Afterward, the students asked their teachers what had frightened them.
The teachers answered, each to his own student, with the same short sentence: "Better always to be afeared."
The tradition, preserved in Gaster's Exempla #291 and echoed in Berakhot 60a, does not describe a jumpy or nervous person. It describes a person of spiritual sensitivity who remembers, through every ordinary walk and every ordinary meal, that he is being watched by heaven. The Rabbis did not call this fear neurosis. They called it yir'at shamayim — the fear of heaven.
A person with yir'at shamayim does not wait for visible disaster to tremble. He walks already alert. When asked why, he does not give a reason. He gives a principle. Better always to be afeared.
Not paralyzed. Not miserable. Awake.