Not to knock the credulity of Mr. Offering or Offering, jr. but I'm a bit surprised that Santa disillusionment didn't come until 3rd grade or so for them. I was Santa-less far earlier than that. No doubt that was in part due to the presence of an older brother, but more importantly I'm pretty sure this was pretty much the norm in 2nd and 3rd grades.
Anyway, just curious. Chime in...