My most simple one is 3 things
1) duct tape
2) super glue
Triple biotic ointment
Quick fact: spider webs are a good coagulant and have antiseptic properties
I think an in depth study of how people lived in the 1800s is a good start. Books are GOOD. If the internet goes down they will become the best source of info
Maybe you could edit your first post with a numerated list of things that have been suggested. You will be able to add to it by editing it further and be able to consolidate things.
I saw that you had asked about meds and first aid. A lot of prepper types store pet meds that and fish meds. A...
Has anyone mentioned toilet paper? If your on septic you can catch the rain from your gutters in a barrel and pour it in the back of the toilet and still flush after a disaster. It's nice to not wipe with a handful of moss or leaves