Inspired by Boris' bellendious zip wire mishap:

Obviously its always safer to wear a helmet and taken to a reductive extreme we should really wear helmets all the time for maximum safety. However, this would lead to everyone looking like a bunch of, well, helmets and nobody would ever get laid.

I have compiled a list of situations in which one might wear a helm. Where do you draw the line between enhancing safety and looking cool?

Space
Riding a motorcycle
Batting
Rock climbing
------- (my line - all above wear a helmet, all below - fuckit look cool)

Skiing
Riding a bicycle
Zip wiring
Climbing a ladder
Team Building activities