Consider: a man feels vulnerable and aware that there are countless dangers and threats in this world.
Intimidated, he pumps his muscles, covers his body with tattoos, speaks coarsely, scowls, adopts 'manly' pursuits and struts in a macho manner.
His manner is overly-aggressive.
Instead of dealing with life's problems - if and when they arise - he actively seeks conflict in order to prove that he is not afraid.
This man has carefully cultivated a persona and public image that stems ultimately from his own fear.
Yes, he looks tough.
Yes, he looks capable.
But is he?
If the man was quietly calm and confident in his own strength and ability to cope; he would not need to prove (to himself or anybody else) that he was capable.