As closetbiker has pointed out, post #29 by SlimRider is offensive and exactly the sort of infantile attack that has made it difficult to conduct this discussion in the past. If unterhausen's statement at the start of the thread is to be taken seriously, action needs to be taken to remove that post and warn SlimRider of the consequences of further infractions.

EDIT: thanks to the mods for acting in accordance with this suggestion...

With regard to the issue, it's understandable that people place a lot of faith in helmets. First of all, many people nowadays are brought up to believe that cycling is dangerous. It is not. The point of mikeybikes post, which gave rise to SlimRider's ignorant and offensive response, is that cycling is no more dangerous than many other activities, including crossing the street, for which nobody believes helmets to be necessary.

Second, some people have fallen off their bikes and banged their heads. It is natural for them to believe that they might have been severely injured had they not been wearing a helmet, and I'd say it is virtually certain that in some cases helmets have prevented some pain and injury. However, the protective effect must be quite small because the introduction of helmets has not (contrary to the nonsense posted by SlimRider in post #23) made a significant difference to the number of injuries. Let's say that again. The widespread introduction of helmets appears to have made little or no difference to the rate at which cyclists get hurt. So, either when helmetless cyclists fall off they usually don't do themselves much harm, or helmeted cyclists tend to have more accidents, or helmets are the cause of some injuries as well as the source of some protection. Whichever, it seems pretty clear that wearing a helmet makes a trivial difference to your already very small chance of being seriously hurt while on your bike.