The shock at finding out as a child that Father Christmas is not real is to be the subject of an academic study by a psychologist.
Professor Chris Boyle, from the University of Exeter, is to explore whether discovering the myth of Saint Nick can cause psychological harm and lead to a backlash against parents, longer-term resentment or betrayal of trust.
The survey of people's experiences of Santa in countries around the world is designed to find out at what age, on average, children learn the truth about Father Christmas, and whether this differs according to location.
It will measure whether the disclosure ruined the magic of Christmas and will also ask whether after finding out, they just played along.
Prof Boyle will also look at whether children reacted angrily to the revelation and how they found out Santa was not real.
The study follows an essay by Prof Boyle last year which explored whether telling a fib about Father Christmas was good for children, especially as the falsehood was bound to be revealed.
"When I wrote the essay, I was overwhelmed by people emailing me to say that they had been affected by finding out about Santa," Prof Boyle said.
"It seemed to be more about the issue of trust, rather than about Santa not being real.
"I want to try to find out whether there was a sense of anger and question marks over other information given to children by parents.
"Many adults will remember how they found out and who told them. This study will attempt to bring that information together and understand a bit more about children and their belief in Santa Claus."
:: The survey can be found at: https://www.exetersantasurvey.com/