“Most powerful is he who has himself in his own power.” --Seneca
UPDATE: I've been thinking why I have bothered to learn self-control. I think the obvious is that I am able to accomplish much more in my life if I don't give into every impulse but instead spend just a moment contemplating the potential ramifications. Another less obvious reason is that if I don't have control over myself, other people will be able to exploit those vulnerabilities in me by intentionally triggering me. I know all about this because I intentionally trigger people's rages myself, to provoke what most people consider "disgusting behavior".
(I love how the "victim" is smiling in this video.)