I think you might have misread/misunderstood what the years listed mean; All four of these are the same blog post, which was posted in 2016, but it was posted t

I think you might have misread/misunderstood what the years listed mean; All four of these are the same blog post, which was posted in 2016, but it was posted to Hacker News in 2016, 2016, 2019, and now 2021.