I've had a few spills where my helmet hit the pavement and I actually saw stars - just like in the old cartoons.

Thanks for posting. We all need a reminder of the basics.

Also - if you take a spill & your helmet bangs against a hard surface, you need to replace it. Even if you don't see damage, there can be internal damage.

And, whilst I'm lecturing - don't leave your helmet in the hot sun, hot cars, etc. The internal material (I'm obviously not a scientist) can begin to deteriorate. Just don't do it.