I perceive a river of sights, sounds, smells, vibes, thoughts and emotions. And that's just a narrow slice. There's also a whole vast continent of nameless stuff too.

Hallucinogens change my perspective of that river. Stuff I didn't notice I start noticing. My careful sample of the river, cultivated over a lifetime, gets jiggled and smeared all over and much that was invisible becomes visible.

That said, I prefer shikantaza meditation.