Good question!
1. Watching a squirrel (or any other animal) provides a perspective on how to be alert and aware of everything going on around you while still being able to carry out essential tasks--making awareness a habit rather than something that needs to be concentrated on. I can still zone-out intuitively and think beyond the simple tasks at hand if awareness is a habit just like driving a car.
2. Life is simple and easy when the priorities are clear. This applies to everyday modern life as well as to someone lost in the wilderness. Lost humans have been known to run or walk in circles (whose direction is generally determined by handedness!) in a panic until finally brought down by injury, hypothermia, or dehydration. A squirrel would go find someplace warm, build a nest, stay put, and sleep.
3. Evasion and camouflage. It's all about being a practical illusionist. Be where I've used the "run around the same tree a few times, then make a well-timed 'jump' to another one unexpectedly" trick more than a few times against human "predators." The hard part of this is trying to stop from laughing out loud when you hear the pursuer say, "Where the f--- did he go?!"
4. How to keep warm in cold weather. Wear clothing which sheds water, insulates when wet, and dries quickly. Sleep in a bundle of fluffed-up, high-loft material for insulation (leaves, pine needles, grass, fur, cattail down). For the squirrel, the clothing comes naturally. For humans, it means wearing synthetic fabrics, wool, or animal fur.
5. How not to cross a busy road.
6. "Protect your nuts." (LOL!)
The definition of natural I use is black and white, and avoids value judgments: Anything created by humans which could not have been also created by another existing, Earth-originating [LOL] lifeform is not natural. But, the less refined, less structured, and the more natural material that is used, the more closely something resembles being natural. Human-created reservoirs are not natural, but they closely resemble natural lakes and ponds created by beavers and geological and hydrological processes.
Amish culture takes avoidance of modern technology to the extreme in an attempt to avoid the disconnect between human life and nature (and God). I think a balanced perspective is probably somewhere between the Amish and the modern approach, but probably a little closer to the Amish because they at least recognize the significance of the disconnect and the importance of avoiding it. The problem is that they seem to take this to a legalistic extreme, and often ignore the benefits of technological progress. Even this is a sweeping generalization of the Amish, as each ordnung has different guidelines.