Its not clear to me why young people, who weren’t around for many previous days or ages, would latch onto this (rather old fashioned) saying, but it has started cropping up all over their writing.
The weirdest part of this is that there has never, in the recorded history of the universe, ever been a sentence that started with “in this day and age”, that wasn’t either a bland truism (i.e., “people are busy”), or that hasn’t conveyed a total obliviousness to everything that has happened previously (i.e., “in this day and age, communication is more important than ever” – you know what killed Romeo and Juliet? Malign fate misdirecting a message. They might not have been able to live tweet their bowel movements, but staying alive does seem like it might be at least a little bit important too).
In unrelated news, does anyone know if there is a minimum age limit on becoming a grumpy old man?