I was flying this year on my birthday and I had to fill out a customs form. I filled out the bottom first with the day, month, year, and then under "date of birth" I wrote the same thing - 2010, not 1975. Whoops. The Customs guy was good-natured about it and after realizing I was in crisis/shock/panic mode from turning 35 earlier that day, understood and had me correct it.