How do you know the second result is correct? Or the third? Or the fourth?
Although if I’m truly honest with myself, even after many years of developing, the true cycle of me writing code is: over confidence, then shock it didn’t work 100% the first time, wondering if there is a bug in the compiler, and then reality setting in that of course the compiler is fine and I just made my 15th off-by-one error of the day :)