Many Kiwis may have been going through life with face blindness and no diagnosis for the condition.
Also known as prosopagnosia, face blindness is a condition where a person cannot remember a person by their face.
The condition can quite often lead to people seeming rude or forgetful, but sufferers say they're not trying to be, they just literally cannot remember a person's face.
Dr Karl Kruszelnicki suffers from the condition and says the key to knowing if you have it too is an inability to remember a face when you see it in a different context.
"If you get confused with people's faces and names, that's a reasonable hint and especially if you can't recognise people out of context," he told Three's The Project.
"Suddenly, you're at the airport and there's this person, and they say, 'Hi, how are you going?' and you think, 'Who is it?'
"It turns out it's your neighbour from next door, but instead of being next door, they're at the airport and you've got no idea."
Dr Kruszelnicki says people who believe they may have face blindness should speak to a GP and a prosopagnosia specialist.
Watch the video for the full The Project interview.