If I was the last person on earth, I think I would enjoy taking all the time I wanted to read. I could find the comfiest couch and all the fluffiest blankets and pillows and curl up and read without having to worry about anything else. I think I would also enjoy going to stores and to parks and outdoor adventure areas.
However, I think I would quickly get very lonely, so although it sounds fun and something that would be great to do for a couple days or even a week, I think I would rather have people around. Even if it was only a small group, doing things with others is much more fun than doing it all alone.