Where lies that fine, fine line between precociousness and being a downright brat?

In what seems like a blink of an eye, the cute three-year old who knew all the words to Rihanna's songs and was 'so smart, we're not sure where she came from', is now the spoiled brat who can't shut up and has no manners.

The next time I see a munchkin singing Umbrella, I'll know what's coming a few years down the line.
And I'm going to make a run for it to get as far, far away as possible.