The main idea in the short story "Papa's Parrot" is how hurtful innocent lack of awareness of others' needs can be.
Harry Tillain has always been close to his Papa, who runs a candy store. When Harry was younger, he would frequently come with his friends to visit his Papa at work, and his Papa looked forward to those visits, and appreciated them with all his heart. As Harry grows older, however, his interests begin to change. The candy store no longer holds the allure that it did when he was younger, and, truth be told, Harry is a little embarrassed by his Papa's habit of talking out loud to the parrot that he bought when Harry began hanging out with his friends at places more interesting to him than his Papa's store. Absorbed in his own interests, Harry never even thinks about how his actions affect his Papa, until one day, his Papa has a heart attack. Papa is laid up in the hospital for a time, and Harry offers to take care of things at the candy store until he is better. While he is cleaning up at the store, Papa's parrot repeatedly utters the words, "Where's Harry? Miss him!" The parrot has learned the words from his Papa, who clearly has repeated them a lot during his long, lonely hours working at the store. Harry has never thought about how his changing interests and activities have affected his Papa; the parrots words make him realize how very much his innocent neglect has hurt the older man.
The moral of the story is the same as the main idea in this case. Through his experiences, Harry realizes the importance of being aware of the needs of someone he loves, with the understanding that his actions have a great impact on his Papa, whom he really does love deeply.