Atheists: have you ever had a religious experience and what did you make of it?

[JuliaL]

Sure, I had a confident experience of immanent transcendence.
It was drug induced and after I recovered, I concluded that the weirdness experienced came from a malfunctioning brain.

I also had a period after a serious intracranial bleed (secondary to a motorcycle crash) requiring craniotomy and decompression. Every day I had many exceptionally vivid sensations of deja vu. I HAD been there before. I was a veterinary student at the time and very personally interested in the phenomenon. Presuming some validity to the sensation I tried repeatedly to expand the events into not just sensation of having been there before. I tried to predict the short term future. If I 'knew' I'd already been in what was currently happening, couldn't I get a hint of what was to come? Specifically, knowing short term future events can be exceedingly profitable in playing the numbers, the lottery or options trading. It never worked, needless to say, and I concluded that my sensations came from inaccurately tweaking a brain circuit that under normal circumstances was excited by actually recognizing a situation that had been previously experienced.
I also had hallucinations of a lilac fog and a hum and some migraines, but these were really prosaic and boring.