"Oh Shit" moments...

Not necessarily, different people respond differently to shock.

Symptoms of acute stress reaction

The symptoms show great variation but typically include an initial state of "daze", with some constriction of the field of consciousness and narrowing of attention, inability to comprehend stimuli, and disorientation.

This state may be quickly followed by either further withdrawal from the surrounding situation (to the extent of a dissociative stupor), or by agitation and over-activity, anxiety, impaired judgement, confusion, detachment, and depression. Autonomic signs of panic anxiety (tachycardia, sweating, flushing) are also commonly present.
The symptoms usually appear within minutes of the impact of the stressful stimulus or event, and disappear within 2–3 days (often within hours). Partial or complete amnesia for the episode may be present.