Act like you are the oldest teenager in town
ACT your age is one of the worst bits of advice we've ever received.
While parents may have got it right most of the time, they stuffed-up badly when they told us as kids to act your age.
For too long, chronological age has been regarded as the most important determinant of growing old.
It's a hangover from ancient Greek society in which beauty and physical perfection were valued and the elderly received social rejection.
Early Romans also thought of old age as a time of mental and physical deterioration.
In the Middle Ages, some Christian theologians viewed ageing as divine punishment for Adam and Eve's disobedience in the Garden of Eden.
Shakespeare wrote in The Passionate Pilgrim: "Age I do abhor thee; youth, I do adore thee".
Very few people die of something called "old age" as medical conditions and accidents usually intervene and we now know economic and psychological factors - lack of finance, friendships and purpose - contribute to an early exist.
To stop acting your age is an effective way of slowing down the ageing process.
Ellen Langer demonstrated this in a seminal study.
Males, 75 years and older and in good health, were encouraged to think, look, act, and speak as if 20 years younger.
Participants played music and wore ID photos, referred to their wives and children as they would in that era and considered their careers to be in full swing.
Compared to the control group who acted their ages, the make-believe group improved their manual dexterity and became more active and self-sufficient.
Impartial judges who studied before and after photographs of the men observed that the faces of those who stopped acting their ages looked on average three years younger.
Maybe George Burns was right when he said: "You can't help getting older but you don't have to get old."