This is a really great trick and one that I will keep in my wallet and use! The only thing I would
add is a couple of Zodiac signs and/or symbols so that BEFORE revealing the birth date, you can tell
them their sign of the Zodiac under which they were born. It's an easy addition and puts some more
distance between the date reveal and the use of the folder.
PS, the Zodiac signs are for
me, not for them, because I have a hard time remembering which one goes with which date. But once I
know the birth date, I would have a way of easily looking up the sign right on the same folder.