Forests are full of life—well I suppose so are cities, but forests are full of non-human life, life which has not been normalized to us, life that scares us—well at least it does me—scratch that, terrifies me. If you kick a piece of moss which was growing on the ground under you or see a bigger piece of wood on the ground and get the brilliant idea to pick it up—you will be met with an entire ecosystem of red and black bugs, insects and spiders which will cause your reptillian brain[1] to immedietly make you panic and run away.
Furthermore, most forms of transportation are useless in a forest. You have to walk everywhere, and there is no infrastructure set up for your comfort. There are no benches to sit down and rest on, there are no stores nearby in which to buy food or drink if you get hungry or thirsty and there is no shelter from the elements except for the shirt on your back. Good luck trying to cycle on the sandy dirt paths.
However, despite of all these cons, I still feel a strange allure toward forests and nature in general. I feel some completionist compulsion to conquer this great wilderness, to map out all of its corners, to build outposts from its natural resources, colonize it. Maybe it's just in our blood, an inherent human impulse that has led humanity, through the course of thousands of generations of men, to become the miracle that it is today, maybe I'm just autistic, who knows?
On a completely unrelated note, have you ever noticed how forests just have paths? Like no one made them. I don't deny that some paths might have been the result of frequent use by animal life, but there are just barren lines from point A to point B that our brains—and the brains of other animals just naturally recognize as the most comfortable path to take—which they do, most of the time. If you wanted to hide in a forest and remain hidden, you not only need to be deep within a forest, far away from anyone else, but you must also pick a point where you—instead of listening to that built-in autopilot in your head—take a completely non-sensical and unnatural turn into, for example, bushes—or denser forest.
Another thing to note is that sound is more powerful than sight in a forest. Every single movement you make, every branch that breaks under your feet, will generate an obscene amount of noise that will travel absurd distances. Now say you try looking around you to see if there's anyone nearby, to see if anyone's heard you, well all of a sudden you're spinning around in place like an idiot scanning treelines. Is there someone there? Who knows? But on the flipside, this can be used to your advantages. Want to know if someone or something is nearby? Just stand still and simply listen.

What can you even eat in a forest? There aren't a lot of plants that even look edible—let alone are edible growing in there. Assuming you're not an expert botanist willing to bet your life on your education, what's left? Meat, perhaps? Well, sure, but how are you going to hunt down an animal? You might be able to fashion some primitive spear or weapon and—by some miracle, actually kill something. It wouldn't really take much. If you hit a deer for example, it would simply be a matter of following the trail of blood it would leave behind as it ran away until you find where it finally bled out to death. But what then? You cut out a good piece of meat and what now? Will you eat it raw? Is it even healthy to eat such meat?[2] How do you know this specific animal wasn't diseased and eating its meat will simply kill you even if you were to cook it?
Even assuming that you brought seeds to grow inside the forest in from the outside world (you dirty cheater) will you even be able to grow them? I mean—is the forest soil able to grow—for example—carrots, potatoes? Can it maintain plant life not native to it? It seems weird, very different from soil you see on farmland or other. My knowledge on this topic is very lacking, admittedly, so I cannot really answer this question myself, but I have my doubts as to using such an idea as a reliable food source. Wouldn't the crops even maturing to the point of being edible take months anyways?