A Dutch "positivity trainer" has launched a legal battle to change his age and boost his dating prospects.
Emile Ratelband, 69, wants to shift his birthday from 11 March 1949 to 11 March 1969, comparing the change to identifying as being transgender.
"We live in a time when you can change your name and change your gender. Why can't I decide my own age?" he said.
A local court in the eastern city of Arnhem is expected to rule on the case within four weeks.
However officials were sceptical about the case, believing there was no legal mechanism allowing a person to change their birth date, local reports said.
One of the judges wanted to know what would become of the 20 years that Mr Ratelband wanted to erase. "Who were your parents looking after then? Who was that little boy?" he was quoted as saying.