I just spent 30 minutes daydreaming about what I'd do if I was the last human on Earth. After some fansical ideas about spending the time learning, building a nest, taking up radio astronomy, I realized I would probably need to spend most my time on food-management and pre-emptive medicine-learning. Boring!
Assuming food-management was sorted, and I didn't go crazy... I'd have to be strict with myself. Up at 7am every day (or 8am, depending on day break), I'd always set an alarm. I'd give up most things computer-related (no point). I'd obviously learn where hardware stores are, supermarkets for most my food, but I'd need to start growing veg and fruit straight away.
Library. Surival books, gardening books, health books. Find pharmacy, rig up kit to generate electricity. Lots of Army bases in the SW have kit like that, that I've (seen) used before. But then what?
Library: Astronomy, research, physics... a last ditch attempt to find ETI? Broadcast my own radio station on AM and FM in case there is anyone else?
I'd not be much interested in travelling around or thrill-seeking. Resources matter, that's all. So I need fuel for electricity; when resources run out, I'll go somewhere else, in a truck full of stuff. Build lots of large signs and message telling people how to find me. Just try to keep busy, rather than lose my faculties!
