It's one thing to be gone for a week or two, but I honestly can't imagine considering a month, much less a world cruise, without internet access. Prior to having smart phones and access to the internet, it was much more difficult to be away from home for long periods of time. Today, it's possible to monitor and pay bills, keep in touch with friends and family, book and change travel and tour arrangements, be easily reached by work, house sitters etc.
My phone also has replaced my camera, alarm clock, and many, many sheets of printed paper.