Do people forget to use common sense when frighten?

Absolutely, I think common sense can leave you if you're scared enough. The bigger the fear, the more you go on instinct. Especially if you don't have time to think things through or calm down. I think that's why they drill people in some things. Like in school, having fire drills. That way it's routine, practically instinct. So when a fire happens and your common sense is out the window (well, mine would be) it doesn't matter. Because the part of you that's too scared to think doesn't have to. You instinctively know what to do. Unfortunately, there are situations people can't predict, so they find themselves in it with no preparation of how to act when they're too frightened to rationally think of what to do.

Of course it happens on real life. Just go to self-defence classes and 1 year after you know everything about self-defence but they didnt teach you how to hold your fears. And your caught by a thief that says give me all your money or i will kill you. Im pretty sure you wont use any of the moves from the self-defence classes because your mind already says that your gonna lose. Thanks for reading :)