Trivial things that make you annoyed beyond expectations?

[Ming the Merciless]

You clearly didn't detect the iron-y in my post!

Too many creases in the way

 

[Supersuperleeds]

I found a foolproof solution to that problem - not owning an iron!

I find it is best not to complain, otherwise I might end up having to do my own ironing.

 

[Andy in Germany]

Customers turning up as we are about to close, or in our lunch break.

Extra levels of annoyance when they say things like "I know you're closed, but I just..."

 

[Dadam]

The way threads on here degenerate into 3 pages of increasingly terrible punning