Hehe, good one.

The main one I remember is the first hallucination I had at sea.

I was sailing single handed from Laurieton to Broken Bay, in one go. Had a beautiful NE'er all day, just got past Seal rocks at sunset. As it got into the night the wind backed (as it often does ) to be more N even NNW. Not wanting to be on a starboard tack, that would take me closer to land at night, I decided to stay on a port tack, but as the wind backed that meant I was heading further & further out to sea. The wind was a steady 25kts all night & I was flying!!.
I didn't worry at all about plotting my position as I knew there were no hazards ahead, I just kept a good look-out (but I was soooo tired).

Just before dawn I popped below to plot position, before I had finished doing that, I ducked my head up to look around....& saw TREE TOPS to the west! with the sun rising behind them. $h!t !!! I got up into the cockpit fast, gybed away from the 'island', then checked the compass, everything was ok there I was still heading S.
I knew I had made excellent SOG, but surely I hadn't made it to Fiji or some undiscovered Pacific Island??.
Looking at the tree tops, I could clearly see the branches & tree top canopies, & below them, at the water line was a smooth white rocky/bouldery shoreline.
The water around me looked deep & clear ahead, so once it was established I wasn't going to run aground, I calmed down a bit, I considered anchoring, getting the dinghy off the cabin top & rowing over to the 'Island' to sleep under the trees. Did I mention I was soo tired?.

My brain spent the next 20 mins trying to convince my eyes that they were not seeing what they were seeing.
As the sun rose further it revealed that the 'trees' were the horizon to horizon cloud band that I now know often occurs, & the white boulders was the sun peering through between the horizon & the clouds.

When I did plot my position soon after, I was 35nm offshore.

It is part of single handed sailing. Loneliness. Tiredness.
Slocum had it, Moetissier had it Pete Goss, Allan Edwards you, me had it, Crowhurst succumbed to it...

Coming back from the 1981 Sydney-Noumea, I changed boats because the one I was one wasn't going to leave for some time. I ended up with a lunatic skipper on a boat that was falling apart and at 19 years of age, I was the most experienced ocean sailor on board. The weather was cruddy, the boat had issues, I had no sleep.

After a few days without decent sleep I was at the helm one night when my father (who had been killed sailing when I was three years old, 16 years before) climbed up the topsides covered with seaweed, and implored me to join him full fathom five......

Joshua Slocum in his circumnavigation in the Spray in the 1890's was visited several times by the navigator from Colombus' Pinta from the 1590's.