I call it "camera meltdown" usually when we are going away for a few days.
Just what gear and accessories do I need. All in head - too stupid to have a prepared list - other half all ready and packed a week in advance an me trying desperately to pack a camera bag (or three) without forgetting any critical part of it.
Now I have smaller camera bodies bag(s) are much smaller and I figured out a long time back that "you" keep a special going away bag with a spare charger, cables, power board, etc for every conceivable current camera-extras need. Just pick up that bag and much of the last minute sourcing is covered. I am working on which lenses to pre-select. Now usually in some sort of waking nightmare before I get up.
The smart money only have three lenses and this is all that they need. But surely this takes all the fun out of deciding what to take on a trip?