I assumed there was some relation between k T log 2 joules and 20 Watts, probably giving some sort of context to how easily or not easily information in our brains could be lost. The theoretical principles behind the amount of energy required to erase one bit, while interesting, doesn't necessary matter for that relationship, does it?

Landauer's principle would come into effect if you had a theoretical "Computorium" material that could perfectly turn energy into computation. Then the computation you could produce per volume of space would be limited by it.

Our brains are (very) far from being the perfect computing material (so are our chips).

The theoretical minimum is only useful here to show that our brains cannot do free work. (Irreversible) computation always has a cost.

The 20 Watts are the important number. Our brains have a certain energy budget and have to perform within that constrain.

the log 2 comes from Shannon coding, because information (tm) encoding is modeled on a bit string of discrete energetic states (something quantum, too, I guess). And there is a transformation to the frequency domain (ie via discrete fourier transform). Entropy is always messured in Watt, doesn't. make sense to equate psychologic information content with physiologic enthropic consumption.

The condescension isn't too helpful here unfortunately (is it ever?). You could have made your initial response a bit less condescending by saying something like:

The comment mentions "Landauer's principle", which provides some explanation: https://en.wikipedia.org/wiki/Landauer's_principle

Here as well, you could have made your comment better if you just omitted this part: "which you'd find if you'd attempt to read what you avoided... twice."

What do you find condescending in pointing that the clear sentence with enough information was edited of its most important part and that presented as "unclear"?

The way he quoted the comment, it's not even visible that "the comment mentions" like you suggest. He kept the formula of the principle and only edited its very name out. Which is a direct name of the entry in Wikipedia.

What do you find condescending when the person asking doesn't show that he even tried to read not only what the original sentence pointed to but also what the previous answer directly links, both times on such an obvious place as Wikipedia?

I see it more either as intentional trolling, or as somebody who could actually profit of learning to read what's already written, and I don't see I'm wrong here. But I welcome if you explain exactly why I should pretend somebody didn't do what he did in my answer, or even more important, what most of the readers would benefit from? I'm much more a reader than an active writer here, so that's an important question for me.

I very often ask here for the clarifications of the statements for which I can't easily find the answers to. But here the editing out in the single sentence couldn't be more blatant.

Next time you ask for a clarification here I expect a list of the sources you approached first trying to figure it out on your own.

I'll be sure to offer my opinion on the breadth and depth of your research.

You are very smart.

You too, Pavel, my dear, thanks for identifying yourself. I know you say it only because it's true.

I'm very impressed how you masterfully contributed to the discussion.

Please don't be so thorny when other users are clearly participating with such earnest curiosity. This is exactly the attitude that Hacker News flourishes under and it's important not to squash it with such dogged ellipsis litigation.