When teacher Dale Irby accidentally wore the same brown v-necked tank top and big-collared disco shirt for two school photos in a row, he wrote it off as a forgetful lapse.
But Dale's wardrobe repetition raised a chuckle with his family, and after repeating the outfit for a third year, he started a pattern which has since made him an internet sensation.
Dale, now 63, has since pulled on the same dated tank top and shirt combo in his school photo every year for 40 YEARS.
His hilarious tradition started in 1973, and when Dale's wife dared him to repeat the outdated outfit, he kept up the joke for four decades.
Now Dale's distinctive (and slightly faded) clothing combo has become an iconic sight at Prestonwood Elementary School in Dallas, Texas.
Pupils would even eagerly await his arrival at school for the annual photo.
As the years went on, Dale's moustache would grow a bit, his hair would thin and grey and his spectacles would be replaced.
But the one constant was his tank-top and shirt combination which he bought at his local shopping mall.
Dedicated Dale, who has just retired after after 40 years at Prestonwood Elementary, is now experiencing fame for the first time.
His local newspaper, the Dallas Morning News, ran a piece on his wacky tradition and the hilarious photos have gone viral, turning him into an overnight celebrity.
He said: 'It all started by mistake. After I got the photos back from the second year I realised what I had done.
'So my wife Cathy, who I met in my first year teaching, dared me to repeat it again for a third year and we didn’t stop.
'The shirt is now faded and the wool vest has several holes but it has all been worth a few laughs.'
Dale, who has a son and daughter with wife Cathy, would put the 1970s attire on for the photo and immediately take it off afterwards.
He’s proud that, despite having owned the attire for 40 years, both items fit him but admits the clothes can no longer be cleaned for fear they would crumble in the washing machine.
The photos of Dale in his shirt and sweater combo are are still kept in the same drawer - and now he has retired he admit it’s unlikely the picture collection will get any bigger.
He added: 'It really wasn’t stylish and, to tell you the truth, it was a little bit tighter in the latter years than it was in the beginning. But I could still wear it and button it.
'I doubt that I’ll wear it again, even in a dare.'