I learned years ago how important it is to shoot the same subject and location over and over again.
The practice teaches a photographer how to form deeper relationships with the subject, and better understand how the primary subject interacts with secondary elements – like the way high tide may introduce a stunning new reflection, or how a blaze of stars in a dark sky might be the missing element that lifts the image to new heights.
Revisiting a subject also serves as valuable “practice.” You cannot develop your skills in anything without a healthy (or obsessive) amount of practice. It always surprises me to find out aspiring photographers think that they can simply photograph their two-week vacations once or twice a year and come home with compelling imagery! It doesn’t work that way.
Run a single loop measuring 4.16667 miles within a single hour. Now do it again. And again. Now keep doing it – starting a new loop on the hour, regardless of how fast you finish the previous one – until there’s only one runner willing or capable of doing so. Welcome to the simple – some might say sadistic – concept of the Big Dog Backyard Ultra in Bedford County, Tennessee.
I'd like to call the more general phenomenon that this is a specific instance of "ghost knowledge": It is knowledge that is present somewhere in the epistemic community, and is perhaps readily accessible to some central member of that community, but it is not really written down anywhere and it's not clear how to access it. Roughly what makes something ghost knowledge is two things:
It is readily discoverable if you have trusted access to expert members of the community.
It is almost completely inaccessible if you are not.
In this sense, most knowledge is ghost, particularly if you take an expansive view of what counts as an epistemic community.