It may be a concept hard to relate to, but age does not seem to have had the same absolute
meaning then that it has today. We take calendars and clocks for granted today, but our
1800 ancestors probably didn't even have a clock in a public place like 'main
square'. As Claire said, they often went by landmarks (ie, did it happen before or
after the "big wind"). I've heard that they often rounded to the nearest
'fifth year' (if that makes sense to you). That's why if you think about it
there are so many people in censuses aged '20', '25', ''30',
'35', etc. I guess that if someone was older than 30, but not old enough to be 40
that automatically made them 35!
To tell the truth, I was excited to hear about 'age rounding' because for a while
I didn't know what to make of my Murrays. Two or three of them were said to have been
born in 1820 (triplets??). Then, my great grandfather - Owen - aged 15 yrs from 1860 to
the 1870 census, and another 15 yrs, from the 1870 census to the 1880 census... only
rounding accounts for this age progression rate.