I've experienced ethic cleansing and racism at its worst.

I don't doubt it. My own grandfather survived Nazi Germany in the Netherlands, and refused to speak about what happened. All I know is some sort of vague story about working on a farm so his family didn't starve. I can only imagine what he saw, and I can only imagine it in comparison to the things that people saw in Poland. I don't know where you're from, or what you and your family experienced, but all I can give you is my most heartfelt condolences.

However, here's the problem with what you're saying. You're saying "I've seen so much worse than these people", when you should be saying "I can't believe we are still treating people this way. What happened to me and my family should never happen again." Even though their suffering may not be as intense as yours (though experiences vary widely), it is important to remember that it is sustained. It is daily for their entire lives, inside of a society that, in many ways, refuses to believe that suffering still exists.

Is the fact that people say you have no idea what racism is a frustrating reality for you? sure. I can comprehend and commiserate with that frustration (and to me, what often feels like a helplessness). What you have to remember is that it's not about you. it's about the people who still suffer.