"Everything You Need to Know but Have Never Been Told" is a controversial book by David Icke, which covers a wide range of topics including conspiracy theories, spirituality, and alternative history. Here's a brief summary:

1. **Conspiracy Theories**: Icke delves into various conspiracy theories, alleging that a secretive global elite, including powerful families and organizations, control world events and manipulate humanity for their own agenda.

2. **Reptilian Agenda**: One of Icke's most infamous theories is the idea that certain powerful figures, including politicians and celebrities, are actually shape-shifting reptilian aliens disguised as humans, who seek to control humanity.

3. **Alternative History**: He presents alternative interpretations of history, suggesting that mainstream narratives are manipulated and incomplete, and that there is hidden knowledge about human origins and the true nature of reality.

4. **Spirituality**: Icke explores spiritual concepts, such as consciousness, the nature of reality, and the interconnectedness of all things. He suggests that by expanding our consciousness, we can break free from control systems and create a more harmonious world.

5. **Warnings and Predictions**: Throughout the book, Icke issues warnings about the dangers of blindly accepting mainstream narratives and urges readers to question authority, think critically, and awaken to their true potential.

Overall, "Everything You Need to Know but Have Never Been Told" is a provocative and polarizing work that challenges conventional wisdom and encourages readers to explore alternative perspectives on reality and human existence.