I was the teller at the recent annual meeting of our church congregation. A somewhat controversial matter came up and a member called for a secret vote. We had no ballots ready made, and in haste, used scratch paper made from election ballots from the previous year's election of officers.
Voting members were told to write "yes" or "no" on the blank side of the paper. Despite repeating the instructions several times, several members put marks by the names of the previous year's officer candidates. It was clear they were confused.
Was your ancestor confused when the census taker came to his door? Was she confused when she was asked questions for her husband's death certificate?
We sometimes assume our ancestor completely understood the questions he was asked. Perhaps he was completely confused and in his confusion his answers have left us completely confused as well.