No, we don't have trouble, but there are some long-standing disputes in the area. At least in Canada, surveys don't always resolve disputes.
We had our camp surveyed, because we hoped that a utility pole was on our side so we could use it for a pole service, and we wanted to make sure a leeching pit and some other things we're doing don't encroach. The pole wasn't on our place, so now we have a new one 20' from the old one.
The owner of the survey company made some interesting comments. He said that there are several ways of establishing ownership, and a legal survey is just one of them. Usage is another way of claiming ownership, and often a judge will uphold usage, if usage conflicts with a legal survey.
Usage is something like your great-grandfather's fence. At least by the law around here, any neighbour who said that the fence is the property line would be about as strong of claim as many legal surveys. I believe this is true, because usage is a matter of common law that predates surveys. Also, because the survey work in many areas ultimately isn't based on anything very solid. Anyway, if a recognized fence and several surveys agree, the neighbour is probably wasting money in court.
What messes up survey work are things like: The great lot surveys weren't that accurate (great lots in the East were laid out in the 1700's and the original surveys were rectilinear even in the mid-west). Many great lot corner markers are lost. Surveyor's stakes are lost or moved. Surveyors often reference stakes that mark other properties. A lost, moved, or found stake down the road can affect the survey for an entirely separate property. In addition, severances sometimes are described in terms of local landmarks that no longer exist; or, the landmarks noted in several deeds actually describe overlapping areas.
All these factors mean that a legal survey in many areas is only a weak claim to ownership. Could be that the neighbour got hold of an old survey and thinks that surveys are rocket science and absolute. But, as you say, 'Why are some people like that?'