Sweet Seventeen

This number is apparently unlucky in Italy, becuase the Roman numeral for the one-seven number is an anagram of the Latin for I am dead. It also appears to be an unlucky number at Wimbledon 2013, as 17 appears to be a significant number for at least four of the upset victims so far.

So this is rehab.

Meaning
It is the age of sweetness and innocence in a girl. Sweet sixteen means basically the same thing.

Use in Normal Speech
When pleading innocence.

"What, me? I'm sweet seventeen and never been kissed!"