1% rule
I hope many of us internalized this early. It's not very accurate, but I try to think of this as meaning that on average, everything I post online is being read by a minimum of 99 people, multiplied by either the upvote count on the thread (for HN) or the number of active followers I have (for Twitter). It has helped me to always think this to myself before posting something.I probably am biased from the culture on these sites but it still seems all to easy for people to still get dragged into fruitless discussions, overly emotional flamewars and trollbait that they will regret later.