There are times when some questions or answers have many comments. In such cases, there's a "show
n more comments" link. On clicking the link, I find, quite often, that the comments that were not shown initially, are often not comments chronologically later than the last previously visible comment but maybe even be between any of the previously visible comments. In which case, I need to go back to the top of the list of comments and work my way down to read the now visible comments.
Why is that?