Anecdote incoming: I was hit by a car while bicycling home one night about ten years ago. I was knocked over and broke my collarbone in two places. I remember thinking at the hospital, "It's amazing I didn't hit my head. A broken clavicle really isn't that bad." (it's basically nature's crumple zone)
Only a couple days later did I think to check my helmet. It had a huge crack on the outside and two smaller ones on the inside. I absolutely smashed my head on the pavement. That helmet saved me from serious head trauma, if not worse.
From a random stranger on the internet: Please wear your helmet while bicycling. There are many ways to end up hitting your head after a bike crash, and all of them are bad.
I second this. A car pulled out in front of me once - I went over the handlebars, landed on my hip and my head whiplashed onto the tarmac. If I hadn't had my helmet on it's very likely that I would have fractured my skull, including all of the attendant risks of serious brain injury.
Only a couple days later did I think to check my helmet. It had a huge crack on the outside and two smaller ones on the inside. I absolutely smashed my head on the pavement. That helmet saved me from serious head trauma, if not worse.
From a random stranger on the internet: Please wear your helmet while bicycling. There are many ways to end up hitting your head after a bike crash, and all of them are bad.