1) Spare batteries
2) Sunscreen/Sunblock
3) Asprin, ibuprofen, etc
4) Antibiotic cream for minor cuts and scrapes
I like the headlamp idea. I even use mine for household chores in dimly lit areas, like the attic.
Also the hiking staff can act as a weapon to ward off hard charging javelinas and the like.
Or it can simply be used to move itzie bitzy spider's web from your forehead. Or hopefully before it reaches your forehead.
The making of a list comment is a good one. Then you can make copies to have available for your next trip.