A Grand Old D---
It was the great Quentin Crisp who said - with reference to old age - that, "...towards the end of the run, you can overact appallingly". Another advantage is that the older you get, the less you give a flying one about what other people think. They'll have reached a settled opinion on you by then anyway, so why bother trying to change it? And on all other matters, again why hold back?
As proof, I give you Josephine Darragh, a Liverpool nan. Her response to receiving the de rigeur card from Elizabeth Saxe-Coburg Gotha von Battenburg on her (i.e. Josephine's) one hundredth birthday last year was perfect in both tone and content and could serve as a lesson to younger people in general, and the easily gulled in particular:
Good on yez, gerl!