There are few things I find more annoying than an obviously insecure person who obnoxiously tries to prove themselves. We're all out here trying to fake it til we make it, but for some reason this is something that quite a lot of individuals fail to understand. What's worse is that they rarely impress anyone else (or at least anyone who's worth it). Witnessing somebody's desperate attempt at trying to be the tough guy is a cringeworthy sight indeed.
At the same time, it can be entertaining from a safe distance. So long as you're not in the firing line for a wannabe Navy Seal, their efforts to be frightening make for amusing viewing. Self confidence is usually a great thing, but it really doesn't work when done at the expense of others. It leaves us with no choice but to cringe and laugh at some of the most egregious examples of this.