A Boy. A Dream. An idiot.
Gideon was born in Varrock to his parents, the local museum curator and an his wife. From a young age, Gideon would display a strong inquisitiveness and yearning for knowledge that many of his ancestors shared. In addition, he seems to be an enormous font of energy and is excessively hyper-active to the annoyance of those around him. However when it comes to understanding simple social interactions, he's a complete fool. He constantly misunderstands simple discussions, is honest to a fault(making him typically unpopular with women), and irreparably ignorant of proper social conventions such as titles and ranks.
Despite this, Gideon is constantly seeking acknowledgement from others. Detached from his own family, Gideon has been known to cause trouble around Misthalin during his 'Training'. Testing various magical techniques, in one incident, Gideon managed to catapult himself over the walls of Lumbridge Castle. He landed near the duke, whom he affectionately referred to as 'Mr Dukie', boasted he would be the world's greatest wizard, and promptly ask him for a quest.
The strange paradox about Gideon seems to be his technical knowledge on Magic and his ability to use it, as opposed to his 'general intelligence'. Magically speaking, Gideon's ability is already quite advanced for his age. While often lacking in focus and complexity, he makes up for it in power and ingenuity. Likely a combination of his genetic disposition for magic, and the sheer unpredictability of his imagination, Gideon is something of a wildcard in real dangerous situations. However, still young, his inexperience and lack of focus often set him back.
Upon meeting anybody for the first time, Gideon is quick to inform them of his future status as 'World's Greatest Wizard'. Gideon has lived his life in constant pursuit of this dream, leaving his parents and Varrock around age 16, and has never looked back. He will tell anybody that he refuses to train at a wizarding academy, but the truth is there is no teacher in his right mind with the patience to teach him. Undaunted, he has set about learning magic on his own by adventuring across Gielinor.
He claims he is gifted with 'Inspiration', and that he doesn't really plan anything, the latter of which at least is believable. New techniques and skills 'just come to him' when he needs them, and that's how he innovates new techniques. At the same time, by taking on ever greater challenges, he hopes to be one day recognized by everyone as the 'World's Greatest Wizard'