That was almost certainly one of your spiritual guides talking to you. Don't give that treasure up, you don't need to be "religious" to continue it. You just need to accept your spiritual dimension (that we all have), which is usually much easier for us when we're kids. Once we grow up, we develop our ego further, which acts like a barrier between ourselves and our spiritual dimension (i.e our guides). Btw, a substance like LSD or psilocybin can break down the ego temporarily and thus open you up further to experience your (natural) "link" to the "other side". And this is the reason why a lot of people report experiences of spiritual nature when they consume such substances (in the correct set and settings). Daily meditation practice is also a very good idea to keep it going.
Don't forget to read to the end...this isn't a 'spiritual' thing.
Still, it lives on. Not many incorrect ideas do. Perhaps it's because it is a more concise and elegant answer to several unresolved questions (why did self-awareness arise? why did religions change at that particular time?) in ways we don't have any other good answers for.
It's a brilliant idea, that sadly happens to be wrong.
Wait, what? Sounds cool and I'd love a source on that.
https://en.wikipedia.org/wiki/Bicameralism_(psychology)#The_...
Basically, before 3,000 years or so, it was common for people to hear the gods talk. Somehow, that changed and it became far more rare, with only a few (prophets and such) claiming to actually hear the gods' voices.
The bicameral theory is that there are still such people today, schizophrenics, and it is one half of their brain talking to the other - but they perceive it as an external agency. And that somehow this was the common state of humanity in the past, but changed. We became self-aware - we recognized the internal voice as part of ourselves.
This does actually fit many historical facts well. Still, it is likely wrong for other reasons.