A person who knows everything is often referred to as an omniscient individual. In literature, philosophy, and mythology, such a person is described as having omniscience , meaning complete or unlimited knowledge, awareness, or understanding.

Common terms related to a person who knows everything:

• Omniscient : Having infinite knowledge.
• Polymath : A person with wide-ranging knowledge or learning in multiple fields.
• Sage : A wise person, often with profound knowledge.
• Know-it-all : Informal term for someone who acts as if they know everything (sometimes used negatively).

In mythology and fiction:

• God or deities are often depicted as omniscient beings.
• In literature, an omniscient narrator is a storytelling voice that knows all characters’ thoughts and events.

If you want, I can provide examples of famous omniscient characters or discuss how the concept appears in different cultures!