But you can't eat money or currency! And it is in my opinion unwise to make assumptions. In this case one assumes food will always be available and people will always be willing to swap it for something. While this may be the case I would say it is better to be on the safe side and have alternative options which rely only on the consistency of nature. Even if it's just one forest you get to know, where you can pick or trap different things at different times of year. Who knows, having an understanding of your forest may just save your life one day. Plus, these kind of adventures are so much fun!