>  > Or with https://ruby-doc.org/core-2.6/Thread.html, see how you directly
>  > have an example of common usage?
>
>  How can a single example of "typical usage" help you understand a
>  complex topic such as threads?  And what is "typical usage" of
>  threads, anyway?  I could use threads in umpteen different ways, all
>  of them "typical".  What am I missing?
>
> I'm sorry but I give up. You'd be able to understand on your own why basic examples are helpful. Try to look
> at sites like stackoverflow and try to understand why people like it.

I guess I'm not smart enough to understand that.

I'm sorry. Whenever I explain something and it looks so evident to me and someone still does not understand my point, I tend to think he has to be trolling me and get a bit upset. I shouldn't have answered that way.

Maybe you are just unfamiliar with the "tutorial" way of learning things. 

I'll try to make an example. It is not perfect. Please try to bear with me.

For quite a lot of people, this page http://ergoemacs.org/emacs/elisp_string_functions.html is much simpler to use & learn from than this page https://www.gnu.org/software/emacs/manual/html_node/elisp/Strings-and-Characters.html

It does not mean that the later page is bad, it is actually more complete, better documented, already grouped in topics... and yet, a lot of people prefer the first page... straight to the point, simple examples.

Please tell me if you are able to understand this, if you cannot I'll try to explain further.

Kind regards,
Philippe