Want to never feel old? Live to 100.

advertisement | advertise on newsday

More than half the centenarians polled for UnitedHealthcare's annual 100@100 survey said they don't feel old, even at 100. For those who did feel old, they said the first age when they had that feeling was, on average, 87. And just as 60 is the new 50, these days, 100 is the new 80. On average, the centenarians said they felt more than 20 years younger than their actual age.

On the other hand, if you do want to feel old, talk to a preteen. As part of this year's survey, UnitedHealthcare also polled 10-year-olds. Their response when asked what age is old: 46.