Perception: A Dangerous phenomenon (when dealing with imbeciles)

Perception: Wikipedia says: The philosophy of perception concerns how mental processes and symbols depend on the world internal and external to the perceiver.
Does this hold true in the world around us? I think, the philosophy of perception these days concerns how mental processes and symbols depend on the world "internal" to the perceiver.

My school teacher used to say: "Isn't perception a wonderful thing? If we all saw everything the same way, there is hardly anything to learn" This would usually follow with: "Next time someone disagrees with you, remember that it is an opportunity to learn a new perception."

Now, after all these years, when I think about what she said, I say to myself, "Do I have to?"
I would like to remind her that when an idiot disagrees with you, he/she will only drag you down to his/her level, and beat you by experience. Why do I need to go through the pain to learn the perception of somebody who doesn't have his facts right, beats around the bush, & to make matters worse, most of the time doesn't even remember what he is disagreeing about after some time...

I do come across such characters in my day to day life at work. The common thread among all such characters is that the statement mentioned by me in the second paragraph above, holds true. Each one of them is of the opinion that the world that they have created for themselves in their mind is the real world.

Most of the times, their statements will begin with, "My concern is that...." This is where I get reminded of some south indian flicks, which show the fight scenes in super slow motion. I can imagine myself jumping a few feet in the air & delivering a drop kick right on their face, just to remind them, that I really don't give a damn about his/her stupid concern.

I would like to ask my teacher, do we really want to learn such a perception which has no value addition at all. My personal experience is that the only addition it does give us, is a severe headache after you have tried your level best to put your point across, & ultimately given up.
This is why, I think that Perception is a dangerous phenomenon, because at the end of the day, the imbecile perceiver will just ride into the sunset in his own dreamworld, while you are left thinking.... "Why me???"