Yes. It happened when I was in my early 30s.
I was having flashbacks to a violent crime that happened when I was 19. The flashbacks were confusing and debilitating, almost hallucinatory. My actual physical world seemed to get darker and darker, and weirdly, it got to a point where nothing looked quite real--it seemed like I could see the molecules things were made of, and that nothing was really substantial in any way.
This got worse and worse in a number of ways, and just when I felt I could take no more and would surely end up in an asylum very soon, I said a prayer I'd heard at Mass, "Lord, I am not worthy to receive you, but only say the word and I shall be healed."
Immediately I felt a 'whoosh' up the back of my spine and out the top of my head into a brilliant loving light that I believe was a part of God. Within this light there was no time, and there was perfect love and perfect knowledge. I didn't disappear as 'me', I just kind of blended in with the light. I saw I was part of the light AND myself, at the same time.
Then, boom, back into my body.
Over the course of the next five years I went through a horrendous healing process that involved huge changes in my life. Every time I felt I could not last, I would think of that light and think, no, I have to. It's the least I can do.
I think I got some help there and that that says more about God than it says about me. In the Beatitudes, Jesus says, "Blessed are the poor in Spirit, for they shall see God." That's me, poor in Spirit. Not very religious, kind of a spiritual dope, as it were.
I sometimes still get a warm glow, like a shot of it, when I am in need. But not often. I think people make too much of theology. If there is a God there just is, no matter what you think or believe. (If that makes sense.) And I don't think the real God is anywhere near as mean as the One people like to yap about. :)