He was probably just unaware, like most people, how hard it is to subsist in nature alone, and how harsh the beautiful landscape can be.
In the right context, ignorance is a kind of superpower. When you survive and it all works out, you are a genius. Many successful people start their story with: "If I had known what I was getting into, I would never have started..."
So yeah, I kind of admire this ignorance ... in other people. I am WAY too self-conscious and introspective to embark on some enterprise where I know that I know nothing.
Oh, and the poisonous seed thing - he was just eating a plant whose edibility was not established. I dunno, maybe people think nature is benevolent, and sure I can think of a bunch of edible plants in the woods near my house ... but I can think of plenty that are poisonous, or mildly toxic, or carcinogenic, or indigestible, or otherwise liable to disagree with you. He didn't know if he should or shouldn't eat it. He was rolling the dice. If you roll the dice and you live, you're a genius and in a few years you get to write your memoirs as the next Thoreau.