Earlier quoted context omitted.
People writing essays about software that are bound to get outdated and will never be read by anyone. I write a lot of documentation entirely with the awareness that no one else will read it. I write it for myself. I don't want to have to remember the intricacies of a system. I want to write things down, then move on immediately, and have the security of something I can refer back to if I need it when I revisit the s…
But doing so is your personal preference, you (i hope) are not required to do so. Some people find it easier to organize their work differently or not at all. Some people are astonishingly productive despite not writing anything down, ever.
Writing code is more about communicating how to solve a problem than just solving a problem, that's how I view it. If you don't communicate, nobody except you will ever understand it. It might be that you don't need to document a lot, maybe most is obvious if the key parts are sufficiently explained. But it's vital and sometimes it's better to write a bit more than a bit less. A thing is, outdated documentation might be worse than none, so it's a delicate balance.