Most genealogists come across people who change their county or parish of birth over several census.
The classic example with my Dodd relatives is Sheriff Hales and the Shifnal district altogether. They are constantly changing between Shropshire and Staffordshire as their county of birth.
A recent discussion in Brick Walls concerned Cradley.
When describing how people change their counties of birth over several census I did not say that Cradley was never anything but Worcestershire in terms of "official" jurisdiction.
What I said was that parts of what is now regarded as Cradley were originally in Shropshire as part of Halesowen.
As soon as your street/farm/business was included in the Cradley district then you became part of Worcestershire.
Before that, the street/farm/business could rightly be called part of Shropshire and some people would rightly regard themselves as being born in Shropshire.
Some people reflected these changes when answering the census. Some never change their county or parish even if their place of birth has been rezoned.
The 1841 census is particularly confusing with the "Were you born in this County?" question.
Telling inexperienced people that "If they were born in XXXX they must come from county YYYY or parish ZZZZ" is counter productive.
They end up searching census and other information based on what is correct from our perspective and the "official" definition.
They also need to consider what the person who was living at the time regarded as correct.