I couple of months ago I flew with an old fella in his 206 from Switzerland. He's the owner/engineer/pilot/everything of a small company with an H300, 206 and Lama. He flies a lot of concrete for construction, but occasionally does give instructions and also flies VIPs to their favorite ski resort.
He insisted on a helmet and it was the first time I used one. Unfortunately the helmet was a bit too large for me, but I could definitely get used to it if you give me a recent model.
He made a point that he flew once with two guys in his H300 (were you are basically sitting on top of each other) and he had to do an emergency landing because of some mechanical failure (drive train if I recall correctly). He was the only one wearing a helmet. On touch down the Hughes 300 almost flipped over and he hit his head on the door post REALLY hard. With his one eye he saw the right passenger open the door and getting ready to jump out, while the ship was still almost flipping and the pilot was afraid his rotor would strike the ground or boom anytime soon. With his right arm he just grabbed that young guy who wanted to jump out and told him to stay put.
The point is, without his helmet he would probably have been unconscious, which could have resulted in lots of different endings of this story. He now also insists on passengers wearing the helmet, "even if it's Michael Schuhmacher".