Never underestimate fate.
That was the phrase Baki would always bicker to him about.
After that he would hear, "Anything could happen" or "You have to stay alert at all times" or "Not everything is controlled by your own hands like a puppet".
Kankurou looked at his pride, and pondered whether these hands, however much he prided them, weren't that great after all.
Then he smirked inwardly, remembering that Baki's now old and stupid and anything that Kankurou does isn't any of his business.
Never underestimate the enemy.
That was the phrase Baki frequently chanted when he was genin.
Following it: "How dare you be that careless?" or "You were simply lucky" or the good old "You should be happy you didn't die… yet".
Whether Baki was being humorous or implying that he wanted his own student dead, Kankurou found the phrase neither funny nor blood-curdling.
Long, long ago, back when he started ninja business, was younger, and was stupid (Temari was nice enough to remind him that he still was) he asked how to become a good shinobi.
Never underestimate yourself.
That was the phrase his sensei held back then.
Continued with a long speech with "Doubt is not to be present in the battlefield" and "Believing in your power is true power" and also "The best shinobi is a proud one".
But then, Baki only just started being jounin, was younger, and was also stupid (there wasn't any "Temari" to confirm whether he still was- Kankurou thinks so).
Kankurou was actually idiotic enough to believe that nonsense once.
But he stuck with it- he liked pretending that he was still a proud genin, still young, and still stupid- believing in himself, instead of remembering that he was in a battlefield fighting for his life.