Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

(2) you genuinely believe that you are significantly more likely to be involved in an accident due to drivers taking less care around you if you wear a helmet. [Good reason though I am unsure that the evidence is there to support this significantly - please correct me if I am wrong. There is evidence to suggest that this may be a factor, but it is far from conclusive]

Regarding number two, if you genuinely believes that you're more likely to be involved in a collision, then cycle training would be extremely advantageous before resorting to wearing a lid.

the key here is being able to *avoid *a collision rather than prepare for a collision.