The lie revealed

Most of you guessed right, I'll have to make it harder next time!

I know how to make an atomic bomb

True.  Picked the theory up for that one in high school, learned more of the nuclear process while getting my physics degree.

I used to be left handed

True.  I was ambidextrous (Latin trans: right handed with both hands) but my teacher objected and made me stop using the left hand.  Unfortunately this was after she had taught the class that "your right hand is the hand you write with."  This bit of nonsense still pains me when navigating.

I can count to ten in Latin

True.  One year of compulsory Latin at high school and this is the result:  unus, duo, tres, quattor, quinque, sex, septem, octem, novem, decem.  July and August are extra months the Romans added to the calendar in honour of Julius Augustus Ceasar, so September is no longer the seventh month.

I was born in New Zealand

Lie!  I was six months old when my family moved there, thus neatly avoiding winter that year, but I was born in England.  We came back to England eighteen months later.

I learned to knit at age seven

True.  Mum taught me on little green plastic needles, and I knitted scarves and blankets for my floppy dog toy.