One of my favorite perception shifts in this life comes from suddenly realizing how big a tree is.
You're walking along, idly thinking or just perceptively assuming that you're passing these giant sticks with branches and big umbrella-tops with leaves, and sure, they're pleasant but they stay still and just hang there providing shade and cool breathable air and most of the time, you don't give them a thought.
Then something happens — You approach a ravine-edge, or some other spot where the tree's roots are exposed. Or your brain just catches your eyes and your perceptive awareness up to reality, for no reason (it happens!). And then you see it.
You see — no, you feel, you really realize – that that umbrella thing is in fact twice as big as you thought it was; that fully half its body is deep underground, and that you are walking through the middle of it.
It's not a cute umbrella of truffula harmlessness, that tree. It's half-subterranean, half light-loving; and its body curves around just so that you, and everything else, can walk and sit and pass right through the center of it. It is a massive hugger of the world; a giant of a living thing that's utterly friendly to being walked on, climbed through, and hung out in. You think you're standing under it, but you're passing through it, standing on it, being held by it.
It creeped the heck out of me at first, to be honest. But I've since come to love the sensation of re-realizing that, of brushing my fingers on a trunk and imagining that I can feel it all spreading out beneath and above me.
Daoists thought that trees were holy because they were always exposed to the elements. Their entire being was shaped by never once hiding from the wind, the rain, the cosmic radiation. They had reality so nailed.
Whenever I realize how big they are, and how I'm in the middle of one, I get a sense of awe and of cosmic radiation, too. I'm such a frail, tiny thing next to this sturdy half-buried behemoth; and yet here I stand, rains of radiation pouring on my head too, and for the moment, we're both surviving it together.