Doug's character arch was always something I admired, and its groundbreaking accomplishments proved invaluable to later cartoonists that would follow Doug's example of a serialized character development driven story, though none were quite as masterfully executed as Doug. Doug learns from his mistakes, takes advice to heart, comes out of his shell little by little each episode.
Doug's difficult journey of self-discovery, as he evolved from an introverted, petty, self-absorbed immature spastic to a friendly, helpful, thoughtful, and mentally healthy boy is something for children to be inspired by. Learning to get to know his bully Rodger and offer him the hand of friendship was was a touching saga. And let's not forget when Doug got over his infatuation with Patti, and earned her respect.
Doug wasn't the only 3-dimensional character who grew beyond his premise, Skeeter, Rodger, Judy, Bibi, and even Doug's father all went through trials and tribulations and ended up better people for it- thanks to Doug. By the end of the series, that cold and unfamiliar town of Bluffington is seen as a rich and warm home. The bully and the love interest are seen as familiar friends. That disconnected sister is seen as an invaluable loved one. All of those hostile kids he was so afraid of are just like him: people. People you look in the eyes and get to know, Doug eventually learned you don't have to be afraid of social situations and his life is rich because of it.
That final scene of Doug and all his friends hanging out in the basement, now teenagers drinking wine from paper cups and playing and discussing the possibilities of the future; it brought tears to my eyes, And I'm sure I'm not the only one. Bravo, Jim Jinkins.