I suppose it would be mostly practical skills, cooking, fixing things. Usually had to be done by people themselves.
Maybe also mental things like navigating (with or without paper map) and remembering their daily and weekly agendas.
What other things would be a big difference with the people today?
I feel like it’s still important to remember the numbers of some important contacts, so you can actually call them using somebody elses phone if yours dies or breaks. But I suppose not many people would bother