It's simple really. Prior to 1912, the largest disaster in passenger ship history hadn't happened yet. You haven't been able to say that since 1912. No matter how sophisticated ocean travel gets, no matter how dope passenger cruises become, we'll never again be able to say that we're living in an era when the Titanic hadn't yet sank. Incidentally, the movie Titanic also hadn't been made yet, which is also a bonus.
The Titanic Hadn't Sunk Yet