You are misinterpreting me. I did not say to "let them go", "keeping silent". I said not to chastise the orignal poster for saying "this code confused me, so I tried to find out why it works the way it does, and this is what I found out".

Certainly, tell him not to use that kind of construct in his production code, and tell him that the documentation does not provide a defined behavior for it, but don't be angry or impatient with him.

And you've blended "learning" with "doing in practice". Just because I learn something (like how crazy this ++X and X++ business is) does not mean I'm going to employ it. Some "swamps" need to be investigated for signs of life, but that doesn't mean the scientist needs to live in the swamp.