Ruzz,
I had a lot of similar ideas, and some much further-out ideas, at about your age. Not sure exactly what survival scenario you're personally concerned with, but...
I strongly suggest you try it, under controlled circumstances.
Set up a "camping" or "backpacking" trip somewhere where you can easily bail out, or take equipment that you plan NOT to use. Make it at least three days.
I'm guessing you'll come back with a "Still Newer Survival Philosophy" from the experience, but it's not my journey of discovery, it's yours, and my guess may be wrong. For sure, though, the time to find out is when you have a solid "plan B" available.
Still, don't let anyone MY age convince you not to even try. As Heinlein said, "It's amazing how much "mature wisdom" resembles being too tired."
P.S. - Be very careful with the wild plant thing. I'm a cautious sort by nature, and I THOUGHT I was being very careful, and I nonetheless had a very bad experience with it.