Parents are human, and exhaustion makes everyone less patient. But children often experience an irritated response to a small mistake as something much larger than it is. A spilled glass, a forgotten homework sheet or a broken plate may prompt an adult to sigh, snap or scold. The child, meanwhile, may register the reaction as proof that they have done something unforgivable.
This is especially true for younger children, who are still learning that mistakes are part of growing up. If the emotional reaction is too intense, they may not focus on the mistake itself. They may focus on the shame of having caused disappointment. In their minds, the correction becomes rejection.
A child who frequently feels that mistakes invite anger may grow into an adult who hides problems, lies to avoid conflict or becomes paralyzed by perfectionism. They are not only trying to avoid consequences. They are trying to avoid the old feeling of being unwanted when they are imperfect.