I get an email about once a month from the same person to tell me how wrong I am about something I've written here. He never signs his full name. He's not asking for an explanation or for any kind of dialog. He just wants to vent. I know the anger actually has nothing to do with me. So I read them, delete them and move on with my day.
The more you put yourself out there to the world, the more likely you are to run into trolls. Disagreement by itself isn't necessarily bad and can actually lead to a better understanding for both parties. But trolls do more than just disagree with you. They take a perverse pleasure in tearing you and your ideas down.
Find any popular blog or a video on YouTube, and there are always scathingly critical comments no matter how many people post about how much they love it.
If you want to start a club or suggest a new theme for the homecoming dance or try out for the basketball team, somebody may dismiss it as a bad idea or flat out make fun of you.
The more a high school counselor or a private counselor interacts with students and parents, the more likely the counselor will run into a few who are pre-disposed to disagree with the advice or to be unhappy with the efforts.
Successful people ignore the trolls. They know that trolls are always out there and they're almost never creating anything great on their own; that's why trolls have so much time and energy to criticize you.
You have to ignore the trolls. If you don't, you'll spend all your time hiding. You'll be afraid to write a blog or try a new idea or do anything that could open yourself up to criticism.
Not everyone is going to appreciate you. But those who do deserve your mental energy and time more than the trolls do.