Well,

Searching page by page, in a 1000 page thread, or even 200 page is not what I have in mind.
Also, the "All" pages disappears when a thread gets around 50 or so pages (this is understandable).

Even using google, it very hard to find information because you cannot limit the scope to a single thread.

Thanks for the hint on using the search while looking at a thread. The answer was too simple, so I could not see it