So this happened some time ago but I didn't know devRant back then.

In school we had to write some code in Java and before the lessen one of my friends said to me that he already knew Java and that it was like a very easy coding language.

Then, when we actually had to code, he was complaining that his code didn't work.
So I stopped coding, stood up and walked over to him. He had only very few lines of code and after reading the error message I told him that he was missing a semicolon in line X.

He then asked me what a semicolon was. At that moment I thought: Oh, it's just that one thing that you put after ALMOST EVERY LINE OF CODE IN JAVA. I showed him where I find it on the keyboard and then I fixed his code (it had way more errors than just a missing semicolon).

I have no problem with helping other people but if that person brags about how well they know Java and then not knowing what a semicolon was, that's just not ok.