In order to determine accurate view counts on pages, Stack Exchange tracks several key factors. It works relatively well, although it does tend to age over time enough that it isn't 100% accurate.
While not perfectly accurate in determining if you have viewed a page, when the software has a record of you viewing a page, it is 100% accurate; you viewed it.
In the case where we absolutely know that the user has previously viewed a page, it would be nice to visually indicate that. Especially since this is literally already built in. All it would need is to pass the resulting boolean flag to the user view in order for the indicator to render.
It could simply be some small green text next to the view count which said ( previously viewed by you ).