In January, 2020, I am embarking on a four-month, round-the-world cruise on MSC Magnifica. I am currently googling for packing tips for four months and other related issues. My question is for those who have actually been on a world cruise. What should a novice world cruiser (I am not a novice cruiser) know? What didn't you know that you wish you had? What are the most important tips you can impart?