Since I'm awake stupidly early, other things I wish I'd known last year:
Make sure you have all the required equipment with you at sign in, otherwise you'll have to go all the way back to wherever you're staying to collect it.
The T-shirts sized up a bit small.
If you're wondering whether to change your pads at Newcastleton or not, change them. By the time you have to change them, you'll be too knackered and you'll end up riding the last descent with no brakes.
If someone manning a feed station tells you they think it's just a little loop into the forest then 10 miles or so along the river bank to the finish, they're wrong. If you believe them, it'll make the rest of the race seem worse than it is.
The riders at the water station who are warning you about headset-deep puddles ahead are telling the truth.
I can do it.