Nice quote. Boy was I WAAAY off. I was just starting to think it might be a quote from "The Unfettered Mind" when you shot that down too.
Well, since no one figured yours out, I guess that means you can start the next one as well, unless you wish to "challenge" someone to come up with another quote?
I leave it up to you, oh mighty Kusojiji!

Oh no.....When I first read your name, I laughed so hard my wife thought I was having a fit. After I told her and the kids what I was laughing about, THEY couldn't stop laughing.
I gave some thought to changing MY handle to "Henna Ojisan" or "Sukebe Ojisan", but it just doesn't suit me...I'm not old enough yet!

Nice!

Ok, here's an easy one, although who really said it first is a point of some historical dispute so maybe it will hold some challenge:

"After victory, tighten the cords of your helmet"

I'm going to give myself a personal challenge, and not even check my references. It sounds alot like something the infamous Oda Nobunaga might have once said after a particular battle (can't remember which one off the top of my head). He may have said it, but can't be sure he was the FIRST to.
Your verdict?

Sorry, I almost forgot to follow my own rules and tell you what I think the meaning of the quote is....Starting to get absent minded...maybe I AM old enough to use that new handle.
Anyway, as I have heard this quote before (or something similar to it anyway) I would venture to say that it means regardless of the number of victories, never let yourself become complacent ie.-"Always keep your guard up." or "Sleep with one eye open." or more appropriately for the time period- "For every spear shaft cut down, be prepared to have ten more sprout in it's place".
A bit dark way of thinking, but quite appropriate considering the time and place. For every enemy struck down, another is made.

Gotchya!! That was a bit too much info, even for an adle brain like me. It can only be one person then....
Tokugawa Ieyasu at the battle of Sekigahara!!
As a side note, that was the battle that Miyamoto Musashi supposedly faught at (for the loosing side) before he had made a name for himself.
Well, my answer is right, yes?

You got it!