I know a guy who doesn’t have a birthday. Andy* was born in the Moroccan desert. His parents were nomads. There were no smartphones in the 1960s and a nomadic tribe didn’t have much use for the Gregorian calendar. And when it came to recalling the exact day and month of Andy’s birth, there were higher priorities.
Twenty years later, planning to move to Switzerland, he needed a national ID. Thanks to some artifact of Moroccan bureaucracy, he found himself with a state-issued birth certificate that listed only a date – 1969, his best guess at the year of his birth.
When he arrived in Switzerland, he needed a driver’s license. Because of the mismatch between required fields and available data, the compromise was an ID with the birthdate 0/0/1969. If you believe the science around birthdays. maybe that was the best thing that ever happened to him.