Has anyone mentioned your helmet?

A friend I was racing with a few weeks ago arrived at the finish line a while after me... she had developed a headache during the course of the race... I think she was wondering if she would actually get to the finish line...

It turns out she had tightened the strap inside the helmet (not the chin straps, but the plastic-ky bit that sits under the helmet itself) so much that it was giving her driving pain