We might occupy the same physical space, but Jakob Johann von Uexküll (1864-1944) didn’t think we all live in the same world. He came up with the term “Umwelt” to describe the meaningful world that’s created by an organism’s body and senses.

His famous example was the tick, which, when it’s knocking around the forest, looks to us like it lives in a hugely rich environment. But for the tick, its Umwelt is basically three things: the smell of butyric acid that tells it if a mammal is nearby, a temperature of around 37 degrees, and hairiness. Everything else may as well not exist.

"Every subject spins out, like the spider's threads, its relations to certain qualities of things and weaves them into a solid web, which carries its existence."

Uexküll thought every organism brings forth a world that matters to it, which is an idea that went on to influence thinkers like Scheler, Heidegger, Merleau-Ponty, and Deleuze and quietly undermine the old picture of animals as passive little biological machines.

We as humans have an Umwelt too. The world you take to be reality may only be the reality your way of being alive allows you to notice. Which I think is especially relevant when it comes to energy. Like Ray Peat suggested, energy doesn’t just determine how much you can do but changes what you can perceive.

When you’re well-energised, you can tolerate uncertainty, stay curious, notice subtle differences, explore alternatives, and respond appropriately to what’s actually there. The world feels open and inviting and full of possibilities to play with.

As energy falls, though, perception itself gets narrower, and the world starts to look more threatening, rigid, and black and white. Possibilities don’t necessarily disappear, but they get harder to detect and act upon because you don’t have the metabolic freedom to do so.

Improving metabolism is basically Umwelt maxxing.