How can I reply to a person who is so relaxed when standing and talking?

Ignore him! Or tell him to put himself in my shoes, or tell you directly, if you are not in my position, don't make those remarks casually, because you are not qualified. Although I know that doing so may hurt those people, they have not thought about themselves, so I don't think it is necessary to consider whether they have been hurt by some words. Well, after all, I must have had some temper when I was solving relative problems, so it is natural to say so.