Oh, I've experienced it myself, thanks to psychedelic stimulants. My materialism isn't absolute, but it's a policy to stop myself believing in absolute crap.
There are many theories out there, but as a wise man said, the chances of ever finding out what's really going on are so absurdly remote the only thing to do is to screw the sense of it all and keep yourself occupied.
Love is the Law! Love under Will!Infinite Eternal Omniscient Omnipotent Hyper-Intelligence of Pure Love
I would unpick the IEOOHIPL but I don't have time today.