Ok, I'm finally about ready to start thinking about my Big Hairy Bike Goal, which is this endurance tour/race, 430 km/267 miles, lots of hills, very scenic, next summer round about now. I have a whole year to be annoyingly detailed and structured, but hey - I like planning

I think I have a handle on the bike training as such, not least from excellent tips given here, but I was thinking - what other tips would you give a newbie to this sort of thing? My last rock climbing trip went over 24 hours, and I learned a whole lot of stuff I didn't know from before, from regular all-day trips. So - what are the things you wish you had known but didn't, before your first endurance event?

Like: don't train just endurance, intervals are good too. Or, make sure you ride with someone, because at 2 am you're gonna be lonely and freaked out. Or - anything else you can think of that you wish someone had told you!