“Oh, you’ve got a little cluster of greys back here!” my hairdresser exclaims. “Really?” I reply, attempting to sound nonchalant as I mentally make a note of exactly where she’s snipping. As soon as I get home, instead of my usual routine of debating whether getting my fringe cut back in was a mistake, I rapidly locate my hand mirror and a pair of tweezers, and plonk myself in front of the bathroom mirror…