Science:  cosmology, quantum physics interpretations, free will versus determinism, consciousness, evolution.

History:  Mesolithic, neolithic, bronze, proto-indo-european  language / culture, beakers, Mediterranean classical, 20th century

Religion: Buddhism, mindfulness, Ramana Maharshi, Christianity (esp. Catholic Church, Judeo-Christian origins, early church, desert fathers, mystics, Eucharistic adoration)

…the bush and Okavango delta of Botswana.  Coastlines (ideally under sail, in the Mediterranean). Cats.  Elephants.  Stars, seen from remote places where the milky way is a cloudy road through the sky.