GRRRRRRRRRRRRR!!!!

That infuriating moment when you realise that, once again, the reason it didn't work is not because you don't understand and are clueless and should give up and go away,  but merely because you made a really stupid syntax error, which you did not spot because you assumed the problem was you were Doing Everything Wrong.

I need to have more confidence in my general comprehension skills, and much less confidence in my punctuation and basic error-checking.