THE human skull is barely 1cm thick. Yes it's strong, but it's not indestructible.
When you fall from a moving vehicle the force of your head hitting the ground can be catastrophic.
On Sunday, Gladstone teenager Matt Bonney did what thousands of youngsters across the globe do every day.
He got on his skateboard and rode it down a very steep hill.
He was not wearing a helmet.
A few seconds of thrills down the Gladstone hill almost cost him his life.
Today he is in the high dependency unit of the Royal Children's Hospital in Brisbane with what The Observer understands is several fractures to his skull and a brain bleed.
It would be easy to cotton ball this missive, but the reality of the ongoing effect these types of injuries have on family and friends is traumatic and the cost to the public health system is high.
Gladstone teenagers are rallying to the cause with a simple message - no helmet no wheels - on Facebook.
And so they should.
One of their mates is battling for his future and they don't want anyone else to endure this pain.
So next time you jump on a skateboard, bike or other wheeled vehicle, please take on board the rally cry - do your head a favour and protect it.