Temple Grandin writes that she first developed her idea of door and window symbols when she was cleaning a bay window in a cafeteria and was trapped between the glass of the window and a sliding door which had jammed. To escape, she had to ease the door back very carefully. It occurred to her that relationships work in the same way and can shatter easily if not approached with care. Later, she uses doors as symbols of the opening of a relationship, again stressing the element of care required in opening either. Grandin also writes that when she was trapped between the panes of glass, no one could hear her call for help. She relates this feeling to her autism.

Being autistic is like being trapped like this. The windows symbolized my feelings of disconnection from other people and helped me cope with the isolation. Throughout my life, door and window symbols have enabled me to make progress and connections that are unheard of for some people with autism.

Before this experience, when she was a teenager, Grandin used literal doors as a symbol of metaphorical progress. Going to a new school, for instance, was a highly traumatic experience since it involved change. It would also involve going through several doors for the first time, so Grandin would practice going through real doors until she felt comfortable doing so. Now, she no longer uses doors or door symbols in this way, but looking back, each door represents a step in a series of incremental improvements as she adapted to her new environment.