'He's very precocious'

[Cornycremegg]

Is that the correct term? Surely the term precocious means very advanced, so you would just use precocious by itself?
Mum in supermarket described her young child in this way to the checkout girl while paying for an apple her son had pinched

First time to hear about the expression, thought it would be correct in that your example is so vivid, anyway, use as you want. It isn't a bad one.

Interesting one. Not quite the same as 'absolute silence' though. Precocious can be differentiated, I think, i.e. slightly precocious, very precocious, as it's not an absolute state, if you see what I mean. You can be slightly further ahead than others.