Google Analytics: why nextPagePath the same as pagePath when looking for where do users go after faq.html

Question

On

http://code.google.com/apis/analytics/docs/gdata/gdataReferenceCommonCalculations.html#navigation

The "nagviation section", it is said that, to find

Which pages are users going to after test.html? 

We can use:

dimensions=ga:nextPagePath
metrics=ga:pageviews 
filters=ga:previousPagePath%3D~test.html

I also tried using

dimensions=ga:pagePath

instead of "nextPagePath" and the result is the same as before.

Isn't this kind of vague, if using pagePath is the same as nextPagePath? Logically speaking, shouldn't it be pagePath if we care about "previousPagePath" being something, then the "next page users go to" should be pagePath but not "nextPagePath"? (pagePath compared to previousPagePath, so pagePath is already the "next" page).

Update:

Also, I'd expect if we use

dimensions=ga:nextPagePath
metrics=ga:pageviews
filters=ga:pagePath%3D~test.html 

We can get identical results, but we don't. We will get only a count of the pageview of test.html. Why is that?