Some ‘odd’ bits of advice.
With an inside cabin, consider leaving the bathroom light on with the door closed. Just enough light gets out through the vent at the bottom of the door to allow safe passage for those who need to wander during the night, but not too much to disrupt sleep.
Check on the type (& nature ) of bathroom shaver points. Most have been fine but (Britannia’s?) shaver points look normal but they won’t accept electric toothbrush plugs.You therefore need to pack a standard adapter. Also be aware that on some newer vessels that the bathroom charging points isolate when the light is turned off.
Considering a Worldie ? On a westbound circumnavigation you will have about 2 dozen 25 hour days. Fine if your young fit & eager but it can feel that you are getting up at 5am for breakfast & oh the embarrassment of almost falling asleep in the Crow’s Nest😂. Believe me, jet lag is a fluffy kitten compared to the hungry lion that is cruise ship lag.
Eastbound circs have a couple of dozen shorter days (& an extra day! )