You have been had.
Because when Christianity rejigged the Roman calendar, in the 4th Century, the monk who was entrusted with the task of calculating and compiling the calendar was a bit weak in math and got the dates wrong.
The mistake has never been amended. According to the original dates, 6/6/06 happened four years ago.
In case you have become a parent today, cease worrying, and bring out the sweets.