Well I think the implication that we can't understand/comprehend these things is itself frustrating and also wrong. Why does one assume that the scale of the un

Well I think the implication that we can't understand/comprehend these things is itself frustrating and also wrong. Why does one assume that the scale of the universe and the scale of that street you refer to are any different? In both cases you are experiencing and considering an estimation of potentially infinite space at an almost metaphorical level as it relates to your experience, plans, and actions. Indeed, you can consider the universe as this thing which is maybe boundless and has so much stuff and might go on forever but for some reason you think it's any harder than realizing that the street may be infinite in space as well, by virtue of continuous subdivision. Before trying to dive in on any estimate of the smallest thing, do remember that smart people once thought atoms were the smallest thing, and then particles, and so on. And remember that the street itself, even just the stretch you're concerned about, is composed of a ludicrously large number of the "smallest" things we current are aware of. If we let go of this idea that at our own size, things are just some number of things that we can reason about (since that's clearly false, do you reason about the billions of living organisms in your own body right now? Could you?) then we can start to realize that smaller or bigger, we're merely consider a continuum at different scales and it's perfectly reasonable for the human mind to do so, it does so every day all the time.