Breathe out completely then stop your lungs and see how long until you get a little dizzy/can't stand it. Depressurization means oxygen is quickly escaping, bu

Breathe out completely then stop your lungs and see how long until you get a little dizzy/can't stand it. Depressurization means oxygen is quickly escaping, but that doesn't mean that people will rationally take a giant breath of air and hold it. I imagine most people continue breathing normally, or more rapidly due to increased stress. Not realizing that they are sucking in less and less oxygen, and begin to lose consciousness.