I don't agree with VF's comments.
Just because you've come through a bunch of accidents without head injury isn't justification for an argument which says wearing a helmet is of questionable benefit.
I've just posted comments by the Helicopter Association of Canada where they are saying,
"HAC strongly recommends to its Operator-Members that they should promote the use of helmets for helicopter flight crew members under all operational circumstances which permit their use."
Also, its not just aerial work for which helmet wearing is sensible but also flying single-engine over hostile terrain (such a mountainous regions) where a forced landing is more likely to happen on sloping ground.
What VF is saying is that he's tossed the coin and for him its worked out, that's fine but is this the best approach to safety?
Is this the message I would give to my son when there is a stack of statistics showing that wearing a helmet can save lives?
"According to United States military research, the risk of fatal head injuries can be as high as 6 times greater for helicopter occupants not wearing head protection."
Each to their own. As for me I vote helmets.