Everyone is outspoken, powerless and stupid. What should we do? How can we make ourselves smarter?

In your case, it's hard for you to think twice before you act. So just be a silent person. Calm down. Only when it's your turn to speak, and it's thoughtful. Don't always say whatever you want. Although you are straightforward in the eyes of your friends, you will suffer in the eyes of others. As the saying goes, you can eat in disorder, but you can't talk in disorder, and disaster comes from your mouth.