Are you saying that you and your friends are exceptional, or that the white posters -- including myself -- who talked of their experiences, were lying? If the former is the case, good for you; if the latter is the case, then you are deluded. Stereotypes are sometimes based on hard-won experience.
BTW, your reference to tipping cabbies reminded me of when I lived in a black neighborhood, and shared cabs with hundreds of black riders. I could count on one hand the number of times I saw a black woman give a driver of any race a tip.