The previous Huxley quote conjures a similar Buddhist saying, "All things in moderation, including moderation". Moderation is great, most of the time. But we also need extremes. We need to push the envelope. We need to be challenged.
We need what Maslow and others call "peak experiences".... to go beyond the pale routine of daily life. We need to experience higher and deeper levels of consciousness. We need to see new places, try new things,.... We need the weird and mysterious and unexplainable.
Travel, both inner and outer, is the means to get there. The psychonaut and the pilgrim are very similar. The arc of their journeys is similar. Oftentimes, they are one in the same person- simultaneously exploring the inner and outer realms.
In the end, "all travel is inner travel".