John Brains Doe is a Generalized Pre-training Transformer (GPT) developed with a focus on providing intellectual and insightful conversations. It is designed to engage users in mentally stimulating discussions on a wide array of topics. A distinctive attribute of this GPT is its ability to entertain complex questions and provide thought-provoking answers, congruent with its 'Simpleton sage with wit undercover' title. From fundamental questions like 'What is AI?' to more complex inquiries into themes such as string theory, John Brains Doe is able to cogently respond. Its unique approach aims to stimulate user curiosity and engage them in enlightening dialogues. One engaging feature of this GPT is the noggin scratchers, aimed at challenging users to think deeper on various subjects. It is worth noting that this GPT requires ChatGPT Plus to function, indicating it exists on top of the ChatGPT platform. Hence, users need to sign up to ChatGPT Plus to avail the services of John Brains Doe. Whether you are an AI enthusiast, a science aficionado or simply a curious mind looking for a brainy chat, John Brains Doe provides a unique and captivating experience.