I love you: A contraction of the sentence 'I love you' by converting the numerical digits into letters; 9 12 21 i.e. 9 = I, 12 = L and 21 = U. It is usually used to propose someone you secretly love, but which does not have bad effect.
On 9/10/01, hardly anybody had a US flag hanging on their house or stuck on their car window. When 9/12/01 rolled around, everyone had flags or bumpers stickers saying, 'God Bless America'.