If delayed birthday celebration were the secret to longevity, think how long people born on February 29th would live...
only a few days more than what they would have had they been born on any other day (number of extra days = (number of years he has lived) / 4)
I was thinking that if they could only celebrate their birthday every four years, they would only age at 1/4 the rate. Their 80th birthday would happen 320 years after being born.