(Thread title was meant to be "1901/1911 Censuses....")
I got a sub to Irish Newspaper Archives for a day which was very useful (will post some queries about that seperately) - using that, I found an old address for my grandfather in his obituary, which I then used to track him to the 1901/1911 censuses (where his name was spelled wrong).
On thing I note is that their ages really weren't recorded very accurately! There's 10 years between censuses, yet my great-grandfather is recorded as 40/57 (17 years difference), great-grandmother is 54/38 (16 years), my grandfather is 7/15 (8 years).. etc. Did people really not know their ages very well or was it inaccuracies by the census-taker? (Hence a great-aunt being Winifred and Winiford respectively.)
The census-taker should be the head of household.
People didn't know their ages well or had reason to lie - usually they would end up 'ageing' less than 10 years though if vain about it. There are claims about people bumping up ages for the pension but that wouldn't actually work, from a required documentation perspective.
This has been noted before - the person who filled in the census form often didn't know, or couldn't remember how old they were, and made a guess at the ages of those in the household. Many couldn't read or write & probably didn't have a filing cabinet or tablet to store & check certificates.
I know my father hasn't a clue how old any of his five children are - I got him a card for my brother recently and he had to ask me how old he was.
I used think it was just the 1901/1911 generation who never peoples ages, but my wife, from a large family was never too sure about ages or dates.
Going back a century, most people did not need to remember their ages. They worked as soon as they were able, they advanced to adult jobs when they were old enough, looked old enough, or could convince an employer of their strength and ability.
If they were seeking a professional or clerical job in local government, they had to persuade the councillors that they were the best candidates, there was no mention of age. The same applied in private employers also, the best applicant was usually one whose father was known to the boss.
People were as young or old as they felt.