Maybe it's because that's how long it takes to mistake something that you've had decades of practice at for something that's easy (compare: writing, walking, playing a musical instrument, speaking, using chopsticks, welding, knitting, reading etc.), but I suspect it's more to do with middle-aged curmudgeonlyness.
I'm all for a bit of tongue-in-cheek ranting about how Young People's trousers are all wrong, that USAnians don't know how to grammar, or that the internet is full of illiterate n00bs who wouldn't know RFC1855 if an avian carrier dropped it on their heads. But there's a fine line between satirising generational culture shifts and classism or disablism, and complaints about other people's cutlery use are too often on the wrong side of that.
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