I only recently started listening and reading the ideas of Terence McKenna. His communication skill and talks do a great deal to guide the mind to new planes of thought and his experiences are fascinating to say the least. Do a search on YouTube; a few I enjoyed:

Eros and the Eschaton “What Science Forgot”

Time and the I Ching

Opening the Doors of Creativity

Talk about Cannabis

Terence McKenna’s True Hallucinations