Your Special Day

Here's a short-but-true story.  I was at an EB Games, and a guy comes in for help with his Nintendo DS.  The guy working admitted to being somewhat not the expert, so I took over.  He showed me the problem with two DS handhelds.  In one hand, the regular DS, which played a ba-dip-ba-dip sound when he turned it on.  In the other, the "broken" DS, played a higher-pitched da-ding-da-ding sound.

They both seemed normal to me, so I tried to think of some configuration setting that could make such a change.  "Is it your birthday?" I asked.  He looked vacant for a second, stunned by such an offbeat question, and then said, "yes, today IS my birthday!"  So we changed his birthday, and it came up with the regular sound.  Switched it back, and the high-pitched sound.  So I was right, that's Nintendo's way of saying "Happy Birthday!"