Here's my bullet-proof tip for solving mental attitude and pace issues on your first brevet. Find some real battle-scarred rando folks at the ride start and ride with them for the day. Introduce yourself, tell 'em your new, and ask if they wouldn't mind your joining them for a few miles. Here it's an easy task, since our RBA rides with the riders. Other clues for finding the "right folks" are anyone wearing a PBP or other 1200K jersey (the older, the better), or anyone who generally strikes you as prepared and confident. Stay away from the racer crowd; you're looking for people to go take a nice easy ride with and whose brains you can pick for all kinds of randonneuring wisdom and war stories. Good luck!