Oh good grief! That sort of nonsense is often suggested by helmet believers but it has serious flaws in its logic. Picking one: it assumes the helmet doesn't itself increase the probability of impact. The simple test to demonstrate one aspect of how it might is: walk under a beam so low that your hair brushes it (or would brush it if you still had hair!
) as you pass. Then put a helmet on and repeat the walk identically and enjoy the impact. Which hurt more? And I leave it up to you whether your head is likely to have a near-miss with something after you leave the bike in a collision.
No I bloody don't! I test them as I leave the parking space and generally decelerate/brake early when possible so that I have more time to deal with any unexpected failures or underperformance (or bizarre actions by other road users). Don't they teach people to check their brakes when they're learning to drive any more? If not, I can guess at a reason why so many more motorists seem to be demolishing inanimate objects!
That seems backwards: surely if you "believe in helmets" then no empirical evidence will change your attitude? Whereas if you are a scientist without beliefs about helmets either way, then you follow the evidence?