I am truely ambidextrous - play me at swingball at your peril, never on back hand you see. My father and his mother are/were both also ambidextrous, although my brother is left handed only - he got the photographic memory so I think he came out tops!!
I'm a lefty, but one of the first things I was taught in window cleaning is that you've got to be able to do it with either hand. Otherwise you have to climb the ladder twice as many times.
i;m left handed i have aleft handed cheque book (stubbs on right hand side ) and a left handed ruler numbers un right to left.
Statistically, and this is a fact, left-handed people don't live as long as right handed people. Its even recognised in the insurance industry!