When energy is suppressed and squeezed into a smaller and smaller container, it eventually can tear the container apart and surge forward. We see it in our kitchens when water reaches the boiling point and the spout of the tea kettle catches the steam. You hear the whistle and know it is time to make tea. The surge is useful information.
But boiling soup or sauce will blow the lid off an unwatched pot. And a quiet subservient person can be carrying unexpressed frustration and pain that grows in intensity until it explodes into violence. The nice, quiet, unassuming person with no criminal record who thrashes out with fists or bullets is well known to newspaper readers and TV news viewers.