Mine were a bit less acute than most cases here. It doesn't rank up to the kind of emotional trauma other people ITT have been through (though I'm not a complete stranger to that, either) but mine was when I realized my health is going to prevent me from ever doing what I want to and getting my shot at a reasonably happy life.
The slow dread of realizing decades of miserable, exhausting, bitter, mostly hopeless, unappreciated effort is void, and has been a complete waste - realizing that things "working out" is not really on the table anymore, and neither's anything else, much: all you can do is keep existing. That is easily #1.
Or realizing friends and family didn't have my back the way I thought and might actually join my list of a zillion problems. That was pretty scary.
Distant third, near misses in traffic - but frankly, I've had a stronger reaction from losing my fucking house keys. Almost got hit by a tram. Meh. Would've lost my appointment, I'm sure. Some shitheel trash in a BMW (because of course it was) tried scaring me by pretending to hit me while out for a walk, I'm like "😐 ... yeah? Make my day - in fact, throw it in reverse and get a proper run-up, you little bitch".
What's the most scared you've ever been in your life?
Spooky season is officially upon us!...
If you look up the definition of 'bully', Duckduckgo gives you results from a 19th century dictionary (i.imgur.com)
Giant kites could pull ships across the ocean – and slash their carbon emissions (www.cnn.com)