I know a woman who was interviewing for a job as an engineer, and was told to meet the interviewer in the company cafeteria at the door. She stood there looking around, waiting for someone to approach -- only to have a man walk up to her and hand her his tray as he was leaving.

Not only did it never occur to him that she was an engineer -- it also never occurred to him that an African American could be anything but a cafeteria worker.