The first hit for the a search of the word preferences is indeed the one you wanted.
The ‘gotcha’ was that the search starts from the selected item in the dialog, and that item will be the last-used key command (except for the key command to open the dialog).
So if you don’t want to wait as you hit search repeatedly and loop back to the top, you need to select the topmost item in the list, and then do your search.