May be he created a new Acoount !!

I think that video talks about something quite different, but it does seem like a good way to think from what I could tell by skimming through it.

The same reason why you see a new "how to practice" blog by a newbie every week (and a couple of CF DMs every day on the same thing). People want to learn effectively, and these blogs related to learning are meant to be an answer to those blogs. A lot of high-rated people I know are fed up with seeing these newbie blogs, so it's tempting to give an answer once and for all, and link to it whenever someone asks such questions.

This is why the catalog is a thing too — you don't need to waste time searching or asking for a tutorial on CF if you don't find one otherwise, like what used to be the norm before.

If a problem has something that you've already seen before — you've solved a very closely related problem or discussed the same setting with a friend — then you can just use the same ideas you used back then to try to solve the problem. It reduces the overhead of having to think about what is important in the problem. For example, if a problem involves $$$ax + by$$$ where $$$a, b$$$ are constant integers and $$$x, y$$$ can vary over the integers, I almost always keep Bezout's lemma in mind.