S E N T I A S A B E R U S A H A

assalamualaikum wbt
peace be upon you.

maybe they didnt talk based on al-quran and sunnah, becoz they dont have the faith like we do. but im sure they talk based on experience and observation, so maybe there is a truth in their saying;

"do not make a promise when your are happy,
do not make a decision when you are angry"

when we happy, we become optimist, we dont think about the consequences, so we simply happily make a promise. till the day the promise itself traps us, then we regret. we have two choices, being dominated by the promise, or break it! but to break the promise or not, is a decision. dont make any decision when angry isnt it. why? becoz we if we become angry we might lose our rational, or worse, be controlled by shaytan and nafsu. so before you want to make the decision, get rid of the anger, take wuduk, make isthikarah, inshaAllah the decision you will make being led by iman and akal.
salam.