First aid kit
You’ll have a first aid kit at home, and there’ll be one at your place of work, so why shouldn’t you need one when you go n vacation? If you’re off on a road trip, then sticking a kit in your car is always a sensible idea, but you can pack a mini travel kit in your luggage too.
Trust me, you’ll be grateful when someone gets stung by a wasp or skins their knee on a bike ride. You can buy a ready-made first aid kit in most drugstores, or you can make up your own. Think about what you’ll need while you’re away; perhaps allergy remedies, indigestion tablets, or rehydration salts.