Exams make everyone feel like the only one who didn’t study enough. That’s the room talking, not reality.

Everyone in that room is comparing their private sense of being underprepared against everyone else’s calm exterior, which is not a comparison between like things. You cannot see anybody else’s doubt, so the room looks full of people who did the reading. The feeling of being uniquely behind is produced by the setting and is almost universal inside it. Half the confident faces are thinking what you are thinking.

Avoid the corridor before the next exam and go somewhere quieter. If you want a reality check, ask one friend honestly how prepared they feel. The answer will usually sound a lot like yours.