What kind of feeling is grumpy?

A grumpy person is like a bomb that will explode at any time. Once it spontaneously ignites, it will harm the innocent.

In Romance of the Three Kingdoms, Zhang Fei is a hero who has been through many battles. However, he has a bad temper and often beats and scolds his men. While he is sleeping soundly, his driver retaliates by cutting off his head and defecting to Sun Quan.

A grumpy person thinks that others will do whatever they say if they vent their temper, but they don't know that losing their temper is headstrong and self-destructive, which will eventually harm themselves.