I have gone on a lot of cruises and really enjoy it. I find that it is a great way to see many places in the world - I would otherwise not see. I think the longest cruise we have done is 12 days. My wife can't be away from our grandkids for more than a few weeks.
The biggest problem would be gaining too much weight if I went on a world cruise. I would really have to be disciplined. Otherwise, I would love a world cruise.