Willner is 25 years old, and combines studying for a PhD in anthropology and religion at the University of Kent with youth work in north London, where he lives with his wife, Adele, a teacher. And he is not alone in his childish after-work habits.

According to new research conducted by NPD Group, a retail analyst, sales of toys to adults have increased by almost two thirds over the past five years, and by more than 20 per cent in just the last year. As a result, the ‘toys for adults’ market (which, by the way, is a careful Google search, best done at home) is now worth £300m – and said to be growing three times faster than the children’s toy market itself.