If you've read any survival handbooks, you're probably aware that they are not written with the notion of survival becoming a way of life. Survival handbooks assume that due to some accident, you find yourself temporarily isolated from civilization and in need of food, shelter and water. And while you're waiting for the search and rescue team to come and get you out of the pickle you find yourself in, you'd like to stay alive.
Let's assume that you find yourself in a reasonably warm place with water. You probably don't have to do much of anything to stay alive. Drink the water and find something to distract you while you're waiting to be rescued. If you have shelter and water, you can probably get by without eating for a week or more. If there is wild food to be had, collecting and preparing it is probably as good a thing as any to keep you occupied until the helicopter shows up.
But the notion of long term survival in an unfamiliar place is an optimistic one. Let me give my reasons. To stay alive anywhere, you need a good deal of knowledge about the place you are in and the support of your community. If you are lost in the wilderness, chances are, you don't know anything about it and you lack the support of a community. Even if wild food is plentiful and you can recognize it, long term survival depends on knowing how to prepare the food and preserve it for times when it isn't plentiful. A good deal of native knowledge consists not only of what plants and animals are good to eat and how to collect them, but also how to process and preserve them and store them against times of scarcity.