My family's entry is completely mixed up. They have named a man lodging at the house next door as the head of the household, so the address is under the wrong name. My father is on there, but my mother isn't, they were both born in 1901 so should be there. My eldest brother is not on, but my younger one is, but the whole household is transcribed out of step.
My sister is on as a child under school age, when in fact she went to school and I am on even though I'm still very much alive. I am the one who was under school age but I have been entered as a 30 year old Domestic science teacher.
My mother and father ran it as a small guest house and we had six guests in that night, including the domestic science teacher. The point is though, that those six people will be missing from their family's entry and after all this time they will have no idea where to find them.
I just hope in the future, people searching for their ancestors don't use the 1939 register, because there are going to be some very mixed up family trees.