You made a mistake and were called in to explain You spoke before having the facts You failed your exam You banged up your car You were late etc etc etc..... To all this just shout out "SO WHAT". It is true that each of these are an inconvenience; yet EVERYONE screws up from time to time and we will screw up even more often if we are hard on ourselves and try to not screw up. The stress of not wanting to make mistakes makes us more prone to such.......so take a deep breath and RELAX......focus on what needs to be done. If you screwed up......ADMIT IT, GET OVER IT and MOVE ON. It happens.....no need to dwell on what was done, let’s just find solutions to be better next time.