I'd say that LD riding is mostly a mental exercise.
My biggest challenge on long rides is trying to keep myself from looking too far ahead, or beating myself up for past mistakes. When I get tired, even the most minor mistakes seem worse than they are, and I'm more likely to make stupid mistakes too.
I try to remind myself of a few things.
(1) It's just a GAME. If I'm not having fun (at some level) or being safe, then I have to stop. Related to that, I try and think about how good a story the current situation will make later. That usually makes me laugh at the absurdity of whatever situation I'm in and I instantly relax a bit.
(2) Rest when needed. If I'm starting to 'zone out' I stop at the next exit and take a 10-minute break. During that stop, I either get gas (if I'm at 1/2 tank or below), or I eat something. After that, I try not to remove my helmet - I just lie down somewhere and close my eyes for a few minutes. It's AMAZING how much longer I can ride with regular breaks. I also know the point at which I need to stop for the night and what times of day I tend to need more rest.
(3) Plan rewards. I often motivate myself by rewarding a good ride with hot food or a nicer place to sleep for a few hours. I once planned the last hour of a route so that I could end up at a Sonic drive-in on the Louisiana/Arkansas border (IBR Leg 3). I visualized a foot-long hot dog for about 3 hours before I got there. Damn it tasted good. I ate it and fell asleep on the floor of a flea-bag motel lobby - still in full gear! I've also used promises to myself about comfortable beds and hot showers too. After Leg 1 of the IBR, when I slept in some of the scariest rooms I'd ever seen, I decided that I would stop caring about the cost of hotels on Leg 2. I managed to hit a string of Holiday Inn Express hotels on the East coast - to the point that I would use the appearance of one after 10pm as my excuse to stop for the night. I never managed to stay long enough to eat the free breakfast, and given the short time I stayed in them I think I spent an average of $50 per HOUR.
(4) Talk it out. I talk to myself a LOT on long rides. I don't mean thinking to myself, but actually talking. I never do this at any other time. I'm not sure it helps, but I think it does. If I think it's getting too weird, I stop and phone someone.
(5) Keep to a routine. One of my biggest IBR mistakes was leaving at midnight to start Leg 3. I hadn't slept enough at the Florida checkpoint, and I was used to setting off at 4-5am, but I was too excited to get riding when they turned us loose at midnight. Bad idea. It rained, there were too many deer, and I 'hit the 'wall' by the time I reached Alabama. I spent several hours during the night stopping far too often to rest my head on the tankbag for 5-10 min. Other riders seem to have made the same mistake, because I ran into several people at rest stops who were doing the same thing and complained about it as much as I did. The next day I had trouble recovering from the sleep deficit, and I ended up spending a few hours in a fleabag motel sitting out the heat and waiting for a storm to pass. I never did sleep, and I got tired of waiting for the storm (turns out I was so tired I miscalculated how it was moving), so after wasting more time I checked out and ended up hitting the storm dead-on. Classic example of how one strategic mistake led to several other bad decisions. On IBA rides I've made similar mistakes - the biggest was ignoring weather reports during a BB1500 and riding through heavy rain for 25 of my 30 hours on one trip.
I had a few major 'freak out' moments on the IBR. In each case, I was able to remember what my plan was for dealing with them.....mainly to stay calm, accept the situation, and move forward. One such moment came when I overslept on Leg 2 and had to toss out two biggest bonuses I'd planned to hit that day (up to that point I was starting to think that I might shoot for a Top 20 finish). For about 2 minutes I literally ran around my hotel room, packing, eating granola bars, swearing, chugging Propel, and frantically trying to sort through my maps. My heart-rate sky-rocketed. Then I sat down, forced myself to laugh, told myself I must have needed the extra sleep (oversleeping two alarms and a wake-up call). I calmly packed up and forced myself to just "let it go." For once, it worked. The day ended up being great.
Another moment came when I was in the Arizona dessert. The wind and dust were so bad at one point I could only ride at about 25mph, and even that was nearly impossible. So I pulled over at a gift shop, looked at tourist crap for a few minutes, and slowly started riding again. It helped. Then there was the electrical problem in Nebraska.....getting lost and nearly freezing in Montana......and the worst storm I've ever been caught in (Mississippi/Alabama border). So many memories! I also pushed myself too far and rode all the way to my home on Day 4 to sleep in my own bed. Everything they say about not stopping at home during a rally is TOTALLY TRUE - I nearly quit the next morning when I had to leave early in a rainstorm. I was also exhausted. If I'd woken up my kids to say 'hi' before I left, there's no way I could have continued.
I must have said "F**K ME" out loud about 100,000 times during the IBR - mostly while riding through Nebraska and Texas.
All this reminds me that I never did post Leg 3 of my IBR ride. I gotta do that sometime . I wrote it up 16 months ago...it's on a computer somewhere around here.