Honestly, I can write good code, just not that day.
It's fun to laugh at bad code, but can anyone honestly say they've never been guilty multiple times. Just look at some code you wrote 10 years ago and feel yourself cringe.
It's Friday, deadline fast approaching, and you think to yourself I'll tidy it up in the next release but that of course never happens and because it works you happily forget about it. Then a few years pass and that spotty faced junior programmer stumbles across it and you quickly have to think of a good excuse to stop him thinking what all junior programmers think "What a dinosaur, shouldn't be allowed near a computer."
This of course fails and you spend the the next 3 months desperately trying to find fault with any code they've written to try and regain some credibility.
I'm not bitter about it at all, but wait till the ba£$%rds annual review, i'll show him.