Q. When I was a boy men who dyed their greying hair were something of a laughing-stock. Now I notice that many 50- and 60-something politicians, rock stars and television presenters have apparently failed to age in the normal way. I wonder whether I should prepare to follow their lead, Mary, or risk looking past it by contrast to my peers? I am only 36, but rogue white/grey hairs are starting to appear in my normally all-black thatch.