Racing roadkill
Guru
That’s a big part of the challenge. You have to be able to ‘compartmentalise’ your thinking. Both for the ride ( breaking it down into smaller chunks, mentally)and dealing with stuff as and when it happens. Get a rough plan of how to get out of theoretical situations you may encounter en route, and deal with anything that crops up as and when required. I plot my longest routes so that I’m rarely more than half an hours walk with a broken bike, from a Halfords / other bike shop, or a train station. This plan has only had to be used twice, over the years, once when I strained a hamstring, and once when someone drove into the back of me, when I was 75 miles away from base. On that occasion the LBS sorted me out with a new rear wheel, and swapped the requisite bits over, then I carried on with the ride.That's a proper adventurer's spirit, I don't have much faith in my ability if things go wrong.