Why does the green door appear to Wallace when it does?

The green door appeared to Wallace when it does as it reminded him of a place that he can escape to and where he'll find happiness.
The green door in the story represented the passageway between the conscious and the unconscious. Anytime Wallace entered the green door, he felt a sense of happiness and well-being.
When Wallace woke up, he was back on the miserable streets of West Kensington. The door was a source of hope and happiness to Wallace.
Read related link on:
https://brainly.com/question/25219216