What does this have to do with math? Not much except... The way that I learned my right from my left is similar to the definition of "even" and "odd".
The definition of even: Divisible by two.
The definition of odd: Not even.
I remembered which was my right hand because it was the one that I used to write with. My left hand therefore was the one that wasn't right.
The only flaw: I was ambidextrous and could never remember the hand I supposed to use (my mom and the kindergarten teacher had rules about such things).
How did you remember? Take the poll in the left column.