I've done the wilderness survival experience, and there are a couple of experiments you can try that will illustrate living off the land:
#1: You will be hungry. Very hungry. To experience why you will be hungry, eat nothing but baby mixed green salad (no dressing), along with a small handful of berries. Stab yourself with a pin several times for each handful of berries you eat (simulates real life collection of berries). You can eat as much of the salad as you want, but you have to eat it one leaf at a time (or put it in a bowl one leaf at a time) and you can only do this during daylight hours. For good measure, let your dog urinate on some of the salad (simulates real greens obtained under real conditions). After several days of this, try to say "arugula" without grimacing.
#2: Related to #1, because after a day of eating nothing but salad and berries (assuming you have the typical omnivorish modern diet), you will be unable to watch a late night Ronco infomercial about a device known as "The Salad Shooter" without immediately associating it with the current status of your digestive system. All that roughage will surely leave your gut "clean as a whistle" in very short order.
#3: For at least 4 hours of the day, walk around the house with your fully loaded backpack. Make sure you explain this experiment to your family so they don't think you've finally blown a gasket. You may substitute an 8-hour day on the job only if that job does not involve sitting for the majority of the time. You can also do any activity that will leave you tired, sore, and ready for a hearty meal that will consist of (yech) only salad and berries.
#4: For the Bear Grylls afficionados, you may eat all the worms, grubs, scorpions, spiders, and road-kill that you can find (or that your family plants around the house for you to "find"). This is your only real hope of avoiding hunger, so you'd better get used to it.
#5: If your hike will take you near fishable waters, you might be able to add fish to your diet. This is only allowed if you can both catch fish AND clean fish (not like an ex-girlfriend who washed the fish with dish soap and a pot scrubber and told me it was cleaned). Roll a die. If its a one or two, you may add a trout to your meal. A three or four means you must suck out a small syringe of blood from your body (simulates real fishing with real mosquitoes). Five indicates that you have to take a cold shower with all your clothes on (simulates falling in the lake). Six - nothing happens for a six, other than reminding you that you should forget this nonsense and pop open a cold one!
Ok, joking aside, if you really want to eat like Euell Gibbons
, you want to hook up with a real person who can take you around and show you not only what's edible, but what is worth your effort to eat. There are a lot of natural foods that take a lot of calories to procure. There are many more that, while edible, taste like !@#$. A very small number are both edible and tasty. Some, like worms, require suppression of the gag reflex for most of us. But your chances of a full belly are much better if you can get over those mental blocks put in place by our parents (babies have no problem eating dirt). You mention being like our ancestors - those people ate stuff you and I would puke over. Wormy bread, maggoty meat, and rotting produce regularly found their way to the table.
The point here is that living off the land is not my idea of having fun. It is a survival skill, like making fire without matches. While backpacking for enjoyment, I don't want to spend hours scavenging for what will almost always be meager fare or food that turns my stomach to eat. I'll gladly carry the extra weight in food to avoid this.
However, I am all for supplementing an already full menu with natural foods. Trout on a bed of watercress and miner's lettuce is one that seems to come together fairly often when I'm creek fishing. Sometimes wild onions find their way onto the menu. Blueberries were a lakeside treat in Yellowstone and Lassen parks. My rule of thumb is that if there's a lot of the stuff, feel free to pick it. If it's pretty sparse, leave it be.