I equate learning any new domain as going into a zoo. You look at each animal on its own and you can learn about difference between animals. You can complete it reasonably in a weekend. But going into wild wild forest is entirely another. (If you are interested, I wrote about it here: https://jjude.com/are-you-learning-a-new-domain-visit-its-zo...)

I learned React reasonably quick. But when I started writing production application, I got into so many cases which were not covered in introductory materials. I found answers to some of these cases via google; I had to find answers to many others by trial and error.

That is why people sharing these type of patterns helps. We all become wiser before getting into wild forest.