TriciaF I tend to agree with the definition of racism as being "prejudice plus power".
I'm of the view that most people have fairly irrational dislikes/prejudices about all sorts of things - e.g. tattoos, accents, mode of dress, etc., and we can't legislate for people's thoughts and feelings.
I am a white, British born, person and I have never felt that somebody dislikes or distrusts me because of my colour. Even if I had had such an experience, although it would be hurtful to me, it would be highly unlikely to materially affect my life. For instance, it would be unlikely to influence whether or not my job application or my request to view a particular rental home would be considered.
I think the story would be different if I were a non-white person living in a country predominantly occupied and administered by white people. Some of those people are prejudiced against me and have a stereotypical view of my character, intellect and general abilities. By the law of averages, some of these people yield a degree of power - eg responsibility for recruitment of employees or admissions of students. Their views about people like me are - consciously or sub-consciously - likely to influence how they view my application/request. It is at this point - where prejudice combines with power to affect my life chances - that I think the word "racism" means more than the fairly commonplace petty prejudices that many people have.