All In Your Head explores the intersection of faith, rationality, and our perception of reality. It takes readers on a journey from a strict religious upbringing to a materialist worldview, and ultimately to a nuanced understanding where God and the supernatural coexist with reason and science. The book delves into complex ideas like the nature of concepts, consciousness, and simulation theory, making them accessible through relatable metaphors, personal stories, and sci-fi comparisons. It argues that much of what we experience—whether spiritual beliefs, abstract ideas, or even our understanding of God—is "all in our heads" yet profoundly shapes our reality. By examining both religious and secular perspectives, it encourages open-minded exploration of what it means to exist and challenges readers to rethink the limitations of their understanding.