Many years ago, in the land of the "I-know-everything" young adult years, I had a big mouth. I verbally stood up for the downtrodden and the exploited, and had an opinion (which had to be heard), on everything. I "knew" so much! Today, I know a little more, but have concluded that less use of my mouth can have better results. More use of the thinking part of my brain has many benefits to myself as well as to those around me. I'm sure you learned this at a much earlier age. But I am slow; very slow.
Now I actually think before I comment, criticize and give advice. The strange outcome of thinking before I open my (big) mouth, is that I am perceived as being more intelligent. I have not capitulated; I have not become a "neuter", nor a wishy-washy person: I still call it as I see it. I just wait for the right time, use a different tone and choose my words carefully.
My mom's favorite saying was "do unto others as you would have them do unto you". Keeping that in mind makes life smile.