Privilege is the fact that when all other things being equal, you still wouldn’t switch places with the person across the table, i.e.:
A skinny woman with the exact same hair, eyes, lips, nose, health-level, and income as a fat woman would not switch places with her if given the opportunity.
A white man with the exact same education level, socioeconomic status, and living conditions would not switch places with a black man if given the opportunity.
A cis-gendered man with the same job, same apartment, same body-type, would not switch places with a transwoman/gay man/woman etc., if given the opportunity.
So when you get on your soap box about how one time someone made you personally feel bad as proof that privilege doesn’t exist, ask yourself if you would switch places with the oppressed. Ask yourself if people who look like you are the ones who really need to be uplifted or protected. Ask yourself if even with the bad thing that happened to you, if you are disadvantaged for the rest of your life because of it. Ask yourself if you’d rather be on the other side of the issue.