KAMBEI: I'm not a man with any special skill, but I've had plenty of experience in battles; losing battles, all of them. In short, that's all I am.
Kambei's definitely tasted defeat before. He seems to feel that it tarnishes him which is why he refuses to take on apprentices. Seven Samurai spends a lot of time thinking about the ways that he's both right and wrong on that front.
KAMBEI: But this is wonderful. It is so good to find you alive. I'd given you up for lost. How did you get away?
SHICHIROJI: Well, I lay right down in the ditch there, in the water. But when the castle finally burned down and then almost fell on me, I thought I was gone.
These two are bound by the shared experience of losing their lord and living to see it. Defeat, to them, is something that goes on and on, and never really goes away. It's a tough way of looking at it, but no one ever accused samurai of going easy on themselves.
TALL SAMURAI: Let's use swords.
KYUZO: There is no need.
TALL SAMURAI: What?
KYUZO: If I use a sword, I'll kill you. It's stupid.
Defeat here is preordained. A combination of skill and observation tells Kyuzo exactly how it's going to go. And since he knows, why go through with it? It's very Zen, man… though clearly the other samurai didn't get the memo.
GOROBEI: You're good!
HEIHACHI: Not really. It's a lot harder than killing enemies.
GOROBEI: Have you killed many?
HEIHACHI: Since it's impossible to kill them all, I usually run away.
GOROBEI: A splendid principle.
These guys are acknowledging that sometimes defeat is inevitable. They understand that it's supposed to be shameful, and yet they've accepted it, even embraced it, and moved on. The irony is that kind of acceptance makes them such good samurai, maybe even better than samurai who'd never known defeat.
SHINO: We're going to die, aren't we? All of us, going to die tomorrow, aren't we?
KATSUSHIRO: Maybe not.
SHINO: But we probably will, won't we? Won't we?
Way to stay positive, you guys! Shino and the rest of the peasants have been defeated so many times they've begun to expect it as a matter of course.