Because, *so far*, nothing has proven otherwise.

They simply haven't run into the person they were looking for yet.

A life of comfort and ease—with a full set of teeth and an unbroken nose—breeds boredom and dissatisfaction.

They crave a rush, some real action!

So, they go looking for it.

And one day, their luck is bound to run out.

If you land a solid punch on the jaw of someone with «uncontrollable» aggression, it turns out they *can* control it after all.