Here is what happens when you get old. When you have the words on the tip of your tongue, you think about what will happen after you say them, how they will make the other person feel, and you involuntarily ask yourself, how will this improve the situation/get me what I want/make me feel better, and you see the whole aftermath before you, you feel the hurt feelings of the other person, you feel your guilt for hurting their feelings, and you feel the irreplaceable loss of a precious day, even a minute, spent with someone you love - lost, lost forever, and all because you let fly with some mouthful of crap.
So, you just stop doing it, and obtain the result you seek in another way, and by the time you get old, your bag of ways is really, really big...