Other than time really, energy is what matters in our life. Without it, I don't think most of us are capable of a lot of things. When we have such a high energy, it's very easy feel like we can do everything in the world but once it's depleted, suddenly even when seemingly easier task become a chore.
I find I have more energy when I go outside, sometimes just for a walk.
I notice that too, trying to go out more whenever I can these days 😊