My iPad for example is not unfamiliar, but I find it annoying to bookmark a site because of how the bookmark button is hidden behind an icon which to me looks like "sharing" (little square with arrow pointing up). Same for searching for text on the page.... it's not intuitive. I have to "think" for too many milliseconds each time just to do those basic actions.
You could say "I'm familiar with Apple's annoyingly unintuitive iOS Safari UX for bookmarking and searching text on the page." "Familiar" has not saved the day in this case.
When I go to a site because I'm interested in their product, I'm not looking for a familiar interface in terms of layout or design replication from previously visited websites. I'm looking (unconsciously) for top level things such as clear presentation and logical, friendly layout. "Logic" can appear as many pathways. "Interestingness" is what humans get a buzz from and reward each other for all the time, so if I get a dose of interesting too, served just right and not too much, then it's a winner.