Via Business Insider:
…do everything you can to make it go smoothly — like, for instance, packing the perfect carry-on.
Even if your luggage isn’t lost (fingers crossed), you’ll no doubt be glad to have a fully-stocked bag on hand at all times.
At the very least, it will spare you the expense of having to buy temporary replacements while your sweater/snacks/toothbrush idle in the bowels of an airplane.
Useful advice. CPAP machines, however, make a bag like that more problematic.