'm probably breaking my own rules and offering "too much too fast", but in light of Attila's pointing out how I've added to a problem, I'll offer these up out of good will. I do, however, ask this: While earlier threads were based on others' work, this is a personal account of my own, and as such it is a sensitive issue. It took me twenty years to even speak of any of it to anyone. Please be respectful.
I have had indeed had Close Encounters of the 1st, 3rd and 4th kinds.
1st kind: On numerous occasions, I have (with witnesses) seen the typical "lights in the sky". Different witnesses, different dates. One was a golden ball that zigzagged through the sky. Another was a streak of light too fat and too slow to be a shooting star, meteor or any other "normal" celestial phenomena. One witness was an astro-physicist (graduate from West Point, with honors) and she couldn't explain this either.
3rd kind: On many different dates, many different houses, I have seen entities clearly not of this world. I do NOT claim to be an abductee. Only a witness. Nor do I believe these were "extra-terrestrials" (although that's certainly possible). Just that these were not human and from "somewhere else". I believe the veil between dimensions is easily lifted. It's like our brains are radios and we can tune into different frequencies, different realities. Sometimes by accident. Or maybe these things WANTED to be seen, I don't know. All I remember is seeing them, fearing them, having my psyche ripped open by them, and often times fainting. However, I will never forget those eyes. I have, later in life, had a gun to my head, seen people die, and been in various other "see your life" moments, and they did little to faze me. That's not "tough talk", either. That's a testament to the degree to which these earlier experiences of seeing these entities had on me. Once you've looked into alien eyes, there's nothing else that compares. It's cerebral overload, and the 3-dimensional mundane world pales in comparison to it.
4th kind: In 2nd grade I disappeared. Literally. In the middle of the schoolyard I vanished for 3 hours. Over a hundred adults combed the grounds and could not find me. What's more, when I WAS found, it was in the middle of the search zone, which was a very sparely wooded area (line of sight was easily a hundred feet and there was little to no undergrowth). Furthermore, my skin was blue from the cold, yet I was wearing a thick (sports) jacket and it was May (the school principal and my brother found me, and they were both wearing shorts and T's because it was a warm day). I only remembered fragments of this story until it was told to me by my family. Later, I checked records (including police reports) and they back it up. I disappeared -- seemingly into thin air -- for hours, in a small area, and hundreds of people could not find me. I don't have any recollection what happened during those hours. To me it seemed like ten minutes. The phenomena of "missing time" associated with UFOs seemed likely, but I did undergo regression years later and did not recall anything. I'm totally left in the dark about this one.
These are the nutshell versions. Let me know if I should elaborate on any of them.
While I do not know if any of these beings were aliens from another planet, they certainly were not from here. Extra-terrestrial, extra-dimensional, the unknown -- Conventional science says none of it is real. Thus, if any one IS real (and they certainly are to me, I've seen 'em!), then all other "impossibilities" must be put back on the table as a possibility. I lean towards extra-terrestrial intervention for ancient works simply due to their seeming obsession with the stars (and by extension, outer space). If extra-dimensional beings built something, would outer space have any more meaning to them than to us? Maybe, but maybe not. It's 50/50. But since most if not all ancient enigmas of structure seem to point to the stars, I'm playing the odds that any non-human intervention was due to extra-terrestrial beings who thus came FROM the stars, rather than extra-dimensional ones.