Misjudge and misjudged

We just generally end up thinking the worst of people. Same thing when done with us, we think how, how did that person think like that? Don't they know me? 

But circumstances reversed we end up doing the same thing. 

So then, should we change our thought process, and not feel bad when we are misunderstood or just not try to judge a person / or their situation making those unnecessary stories in our head?

Both are choices that will lead to a lot more peace of mind, but happiness is when we will be able to achieve both.