I admit I don't always understand some things about other cultures, or class differences, or religions or races etc. I am one of the ones who does not think it is absolutely possible to do so. I think straight people can be (or try to be) empathic to me but not understand what I mean about some things. I think I can be (or I try to be) empathic about somethings that I know I don't fully understand.
Perhaps re-reading the Prince and the Pauper or The Color Purple, or Invisible Man, or Bastard out of Carolina or Dispatches, or Sense and Sensibility or so on would help.