the password

I had an interesting patron interaction yesterday. A dad helped his daughter, who was about twelve, sign up for a library card so she could find books for a school project.  

When they handed me the card application, I noticed the spot for a pin/password was blank. Most people pick a four-digit password for their library cards, though sometimes a patron will take advantage of all fourteen letters/numbers and come up with something wild. 

I asked for a password, but the daughter was struggling to come up with one. Dad finally intervened and told her to "use grandma's birthday since she's not using it anymore."

I nearly fell out of my chair.  It took every bit of professionalism I had to keep my big mouth shut.

I tried to tell myself I must have heard wrong, but nope, that was not the case.  When I gave the daughter her card, dad nudged her and happily exclaimed the card used to be grandma's favorite color.

I kept sneaking looks at the dad as I helped them find books about the daughter's school project.  He looked normal.  He looked kind.  He didn't look crazy.  I will never know why he said what he said and how casually he said it, but I will forever be curious.