You too can absolutely amaze everyone you know as you introduce this to them.
I had lunch with a friend today who told me about a neat little math trick.
Take the age you will be this year (2011). Add the year you were born. The sum of the two numbers seems to always be the same number no matter whose birthday is involved.
Try this on your mom, your dad, your siblings, your neighbors, your co-workers, etc., (you get the point).