That might be oversimplifying it but it definitely seems like racial minorities think racism is a bigger problem than white people and women tend to feel that sexism is a bigger problem than men.
Of course it is a bit oversimplified - I've lived being a black person in poor, high crime, but diverse areas all my life, and traveled to many other parts of the country which allowed me to compare different places, and most white people I talk to think racism is a bigger problem than I do. Just came back from a friend's house, where her boyfriend insisted something was sexist (the "Blurred Lines" video) which she thought wasn't.
But aside from that, I think the largest part is because human minds don't naturally work scientifically. People give far more weight to personal experience than to statistics. People notice and remember grand dramatic things more than small continuous ones. People notice things that confirm what they believe and ignore things that conflict. And people find ways to see what they were expecting.
If you have been told your entire life that cops target people like yourself, then when you get pulled over for going only 5mph over the limit, you see it as an example that confirms what you expected, while if you haven't been told that, you think the cop must be filling his quota. The reality is both are wrong - there is no secret unofficial speed above the limit that cops are suppose to ignore. The legal limit is actually limit. If you get pulled over for driving 5mph over the limit, its because you are breaking the law.
If you have been told your entire life that racism is everywhere, then if no one comes to help you in the store, they are ignoring you because you are Black. If someone DOES come to help you, it isn't because they actually want to help you, its because they want to keep an eye on you because you might steal. If you believe you can accurately determine other people's motivation by intuition, and that your personal interpretations of your expressions reflect society at large, then when you see what you are looking for, it means that racism must be everywhere.
I'm not saying that there isn't real racism. The objective evidence says there is. I wrote about that here:
http://biodieselhauling.blogspot.com/2013/04/race-whites-still-winning.htmlWhat I am saying is that individual people stating their subjective experiences is not evidence either way. Of course everyone thinks whatever their own personal issues are are the most important issues, because humans are naturally self-centered. Gay people think homophobia is the biggest problem, and fat people think sizeism is the most significant, and the unemployed think employment is. Poor people are focused on welfare, and rich people care about taxes. What would we expect other than minorities thinking racism is a bigger problem, and women thinking sexism is a bigger problem? Wouldn't it be kind of odd if that wasn't the case?