The author packed a backpack and carry-on luggage for a weeklong cruise on board Royal Caribbean's Wonder of the Seas.Joey Hadden/Business InsiderI sailed on Royal Caribbean's Wonder of the Seas, one of the world's largest cruise ships, in 2022.I wore a backpack and brought a carry-on suitcase for the seven-night Caribbean cruise.I was glad I packed light, but had some regrets. I longed for earplugs and warmer clothing.My first cruise was a huge…