Peter F wrote:But headcwas fine thanks to my helmet.
ssshhh. Don't say that!
Ha ha - too late!
If the helmet was just "cracked" it performed no function other than to deplete your wallet and add to the landfill. To be of any functional use, the polystyrene must be crushed flat. This will absorb enough head-bang force to reduce the degree of headache and might even mean no-concussion rather than light-concussion.
Best not to rely on the things, really; and to look out for the sheep etcetera instead.
It's remarkable that so many experienced cyclists, especially the ones who have fallen off, don't recognise that a head is rarely banged in a cycling fall, sheep-involved or otherwise. When the head is involved, it's generally the face wot gets it. A helmet generally offers no protection to your face, unless its a-one o' them full-face MTB things (a sensible article to wear when MTBing, in my own opinion). In fact, a helmet might even make your face (or neck) injury worserer as it levers your jaw harder into the road.
How was the sheep, by the way. I yam a-one o' them exasperated humans now less concerned about my own species (stupid lot, we are) than I am about the innocent beasts being punished by stupid humans all over the place.