Have you ever noticed how someone can say 1 negative thing and you feel deverstated, maybe you mull it over in your brain for days, not sleep well because you can't stop thinking about it or just feel really angry.
Compared to someone saying 1 nice thing, which lingers for a few minutes. Then its impact is gone and you're on with the rest of the day.
Technically these things should have equal impact so why does your brain not work that way? Well here's my take on it. I hope it helps you understand and therefore work with your brain instead of against it.
A couple of things to think about.
1) What do you hold dear? Your values and beliefs are deep routed, you hold these very sacred. If the 'negative' comment is challenging these, you end up with a very emotional reaction because it's like they're challenging the very person you are. Look at any relious conflict, someone holds a belief which they've based their life on, someone else comes and says it's not true and hay presto we have a very strong emotional response. They only need to say a few words.
2) Conscious vs unconscious. I explain your unconscious like a massive filing cabinet full of all the experiences, sights, sounds and feelings you've ever had. And your conscious can only hold a small amount of information. If you've heard you can't do it often enough you have a huge filing cabinet full which says that is true. One small comment saying the opposite is like a single water droplet in a large pond. It just doesn't make an visible impact.
So what do we do to change it?
1) Know what your beliefs and values are and make a conscious effort to understand that not everyone's is the same and that's ok. They're not criticising you they're mearly posing a different way of looking at life. Neither view will be wrong, just different.
2) You can override the unconscious filing cabinet by filling those files with something else, once there is enough of them you'll start to believe it. Tell yourself the positive thing over and over again. See it around you, look at pictures relating to it, fill yourself with it. Allow yourself to notice and take in that positive comment and give a genuine thank you. Soon your filing cabinet will be telling you something new and it's the occasional negative comment which seems out of place.
Have a great weekend.