Courage is simply doing things easily and comfortably that other people would find scary.
Thus what is deemed courageous changes depending on what social group we're in.
For example, in certain groups of men it is not considered a great feat to ask a woman out on a date, but in other groups of men it certainly is.
So this insight can be used to do more things which we currently deem to be courageous. Thinking that many other people probably don't think [insert action here] is scary can reduce our fear.