Yeah, it was... not subtle, but also entirely subjective. I gained a lot of insight into what folks have meant all down the ages about ineffable experiences that you can't confirm outside of yourself or properly explain to other folks.

And I think you're right about folks not having belief in anything non-material, but maybe even more important is a lack of gnosis - before my unexpected and memorable experience while meditating, I literally didn't know what the heck religious folks were talking about. I knew about what they were talking about, but I didn't truly know what I was missing by not getting it.

At any rate, these days, technically, I still accept the possibility that all of this might be within me and not evidence of how reality is outside of my own mind, but I have no counter-evidence either, and believing it's real gives me a better life, so it's not a hard choice.