Mr Hamilton; even if you know where your head is, mine is up my arse which is why I have slightly padded seats, by having a helmet on your head and where you might have missed the ground with a bare head but hit with a helmet means this...the impact was so slight to the helmet it didn't affect your head the least bit. But I disagree with you saying that you can miss your head all the time, I know you said in some cases, but in those some cases, and hitting your head you are better off with a helmet than without one. Of course wearing a helmet can't stop concussions from ever happening, not even wearing a motorcycle helmet would do that, and there is no helmet on the market that promises it can eliminate head injuries, but it's design to help reduce the chances or the severity of head injury including concussions. It's not any different than wearing a seat belt, the manufacture of the seat belt doesn't say it will eliminate injury and or death, but we wear them because it can reduce the severity of those problems and reduce the chances of dying which is what a helmet does. We don't really know the percentage of lives helmets save but it's significant enough that doctors recognize the importance of them, but even if the percentage was low, say only 5% it's still worth the chance that the helmet may work to make it worthwhile to wear, personally, and this an uneducated guess, that helmets work about 75% of the time. Also keep in mind that statistics you see on the internet showing cyclist deaths increasing is mostly due to aging population that are riding bikes more than ever, and older adults are far more susceptible to any kind of injury but especially to even a slight knock on the head, this why when old people slip and fall they break hips, shoulders, etc and sometimes die from the head impact; but again there are a lot more older people riding than ever before and in fact it's the older baby boomers that are fueling the sales of bikes to record heights, once the baby boomers start to get too old or die off bikes sales will cool down, but that just goes to show you that we have a great deal more older people out riding bikes than ever before, but it will be shortlived, maybe another 20 years at best, unless the Gen X's pick up where the baby boomer left off, but so far the trend isn't there for that to be happening, but it's also too early to tell, but physical fitness related ideas is all but lacking in the millennial generation Y so bike sales will fall off hugely at some point in the next 25 to 35 years-that's my prediction.