Ctrl-F, "If UFOs are real", someone actually wrote that in this comments section. Yes, the concept of objects that are in the air/flying and you can't identify what they are, is real, and that commenter was using the incorrect definition of UFO=aliens...

Yes, I think the reminder is helpful. In fact I saw a fella on HN argue that because some rocks on Mars looked a bit like faces, we should consider the alien possibility. (This was many months or years ago; HN becomes an orange blur after awhile, but it was surprising enough to stick in my memory.)

Edited to tone down the intro sentence a bit.