Wow, I had no idea that this quote would be so controversial. I will attempt to explain.

To begin, I think there is something that can be learned from the quote, but I wouldn't call it a "deep insight." Or, at least, I wouldn't have before uninverted's reply. Silence, a friend of mine, was making fun of the focus of many anime on literal, physical strength, often detached from anything to protect or, indeed, any real overall goal at all (I don't remember if this is the case with Prism Ark or not). It's thus a light warning against focusing too much on method over end results.

Also, if there were two of you, it'd be impossible for you[a] to be decisively stronger and more skilled than you[b].

Uninverted, I'm guessing, was thinking of akrasia and overcoming cognitive biases, which can be considered "part of self" and, at the same time, something to "defeat" as easily as possible. Hence, the quote can also be read as a summary of rationality.