For as long as I can remember, I've been unnerved by passive infrared motion detectors. You know the ones, those that have a milky-white lens and on occasion blink red when they detect motion. They're absolutely terrifying to me and I don't know why.

I got a few other strangely specific phobias as well - I hate bathroom extractor fans, specifically in bathrooms with high ceilings (which are very common here in Europe), I can't bear to be near industrial light signals even if they're off, and when I recently went to the US, the absolute ubiquity of emergency battery backup light fixtures paralysed me in more than one building. My worst irrational fear is that of horn-style speakers, especially in public spaces or industrial settings, and in those, especially those that fire downwards. (Incidentally, sirens on emergency vehicles, even when they suddenly go off, never triggered this phobia)

So apart from my weird damage, I have to wonder - what are some of your weird uncommon phobias? I don't mean stuff like a fear of needles or spiders, those are quite common and well documented, but something truly odd you can't make sense of and you kind of know should not be able to scare or disgust you.

There's plenty of stuff that's supposed to be creepy out there, but then there's stuff that really shouldn't be unsettling but, for whatever reason, has a really powerful effect. These are different for everyone, but I'd wager we almost all have them. They can be at the level of a classical "phobia" or something less pronounced but still puts you on edge.

What is an example of something that creeps you out more than it should, and why do you think it bothers you so much?

For example: I've got mild issues with what I'll call "big dark things within emptiness." I'm sure there's probably a very specific term and associated subreddit for this, but I don't particularly enjoy searching it up.

An example would be looking at a planet in Celestia or Google Earth, especially the unlit side. Another example would be seeing the hull of a submerged ship underwater. I have no idea why these kind of things give me the willies, but they do.

Intellectually I think it's absurd and will often try to will myself to ignore the nonsense feeling based on completely unthreatening stimuli, but that doesn't seem to alleviate my instantaneous lizard-brain reaction. For whatever reason, I can't get past it.

It's been this way for a long time, too. I can remember when I was very young, I had a picture book about space. It had shots of all the planets, most of which I was fine with, but there was a close-up of Jupiter in shadow that I would deliberately avoid looking at.

Another book had a very dark picture of a giant squid that caused the same reaction in me. I remember memorizing the page numbers for these two photos so that I could skip them whevener I looked at the books. If I ever opened the book to a random page, I would crack it ever so slightly so that I could peek the page number to make sure it was safe.

Do you have something like this? Some absurd fear, phobia, or aversion to something strangely specific or benign? When's the first time you realized it? Has it stayed that way over time?