Sweet Nathan!! Getting into the gear is soooo fun! 
And @Tony, I wore Ken’s little blue knee slip things. Are they knee warmers? Whatever they are, they didn’t have any padding in them, but were decently thick. Ken obviously knows what they are. 
They didn’t chafe me at all, though at times they were annoying because they bunched up behind my knees. I think I’m going to wear just Ken’s knee thingajiggers from now on (instead of actual bona fide knee pads), because I haven’t had a run-off-the-front-and-die episode since that one before RTL and I’ve ridden quite a lot since then all over the place in high gear without kneepads. I know, I know, dumb. but real hard kneepads are so annoying! (at least I think they are…) As fatigued as I got Sunday, my only UPD was right at the end when the bearings in my left pedal seized. I was in first gear doing about 6 mph, and it was humiliating 
Yeah, I get unstable sometimes when climbing in high gear, too. It’s kind of a pain how hard it is to push the high gear up a hill when you don’t have much initial speed to work with. Nowadays, pretty much, I always make sure to let myself shift down instead of trying to muscle it out at ~11-12 miles an hour in high. It may be slower to shift down and spin up at 9-10 mph, but when you get to the top, you’ll be able to kick it right back into high gear and pour in the juice to get right back to cruising speed with no holy-crap-i’m-really-tired penalty :). When I try to muscle up hills in high gear at a sustained 11 or 12 mph, my legs are fried by the top, and I spend a long time resting at 13-15mph after the top before my strength comes back. The slowest I ever let myself go in high gear before I shift is maybe 14mph, and I start getting iffy at 13… if I can push it really hard and keep the high gear above 15 or 16mph and just sprint up a short climb, I do, but if the hill is longer I’ll usually just put in some decent power and watch my speed go down to 13, and then just shift and spin up at 9-11 mph till the top of whatever it is. That way my legs never really get fried from climbs, and I don’t usually fall from hitting a bump too slowly in high gear on a climb and failing to accelerate back out of it from tired, used up legs. (But the shorter ones deserve to be sprinted like heck
:))
And @John, yeah, salt tablets are a superly good idea! (I’ve never taken them before… but methinks they make sense now that you mention it.) I think I push a bit harder for the same speed on my unicycle as I would on my bike for an “equally acceptable/satisfying pace” (23mph on my bike is about as satisfying as 18.5mph on my unicycle for cruising, but I don’t work as hard doing 23 on my bike as I do to hold down 18.5 on my uni.) So… I think that the extra power might mean that we run out of sugar and salt faster holding down a comparable pace on a unicycle.
I do notice that on my uni, I run out of leg energy and start to feel weak much more quickly than on my bike if I don’t stay GU’d up and keep food and water in me regularly, whereas, when I’m on my bike, I can pretty much just eat a Clif bar and go ride hard for 50 miles without running out of gas or getting that “weak” feeling where your brain says “go” and your legs go as hard as if your brain had only said a quarter of a “go.”