Again, just curious (and feeling chatty I suppose). For me, I can only recall a few times I felt truly apprehensive while paddling over the last 28 or so years. Once, fairly early on while paddling in approx. 7-foot post-hurricane swells near the mouth of Narragansett Bay in Rhode Island. I discovered that paddling in long wavelength waves where you lose and gain the horizon is not at all like an exaggerated version of paddling in 1-2 foot chop, but is qualitatively different and takes some getting use to (I didn’t get use to it on that trip and as I haven’t been in such conditions since, I still haven’t); once while paddling back to the ramp in my first kayak, a Sealution II in somewhat modest following seas (the Sealution didn’t have much bow volume and I learned about bow burying); once not that long ago paddling a twitchy rental boat in following seas (I think it was a Looksha but I may be mistaken - to me it felt twitchy but not sure what other’s experience is), once while paddling in a 35 kt tailwind that came up while I was camping in the Norwalk Islands in CT (I tried to wait it out but after a couple of days felt that I really had to get back to work). There have probably been a few additional times I can’t remember. These were situations in which I actually felt nervous and trembly. Another time I was coming back from a full day’s paddle in Bulls Bay SC and found some tall chaotic wave activity along a bar (I think the tidal current was opposing the wind or something) that stretched too many miles for me to want to go around. In that case, I didn’t feel nervous as I could avoid the bar by taking a much longer and physically exerting route through a windy salt marsh.
There have also been a few animal experiences that made me quite anxious. Once while unavoidably paddling over the top of a large alligator (I’ve been around them often enough by now to not care all that much but still try to keep a respectful distance), once while paddling alone, pretty far offshore from Elliots Key in Biscayne National Park when I started hearing mysterious snorting sounds (turned out to be sea turtles), and one time in the Chesapeake Bay on a day with no other boaters around when I saw what looked like 100’s of shark fins a bit off in the distance, and then closer and closer and closer until I was surrounded. Turned out to be the pectoral fins of a humongous school of cownose rays as they swam in the shallows looking for shellfish.