Brain farts are also a huge problem in racing. The simple fact is....that to stay fully consistant and drive your absolute best, It is absolutely crucial that all your focus and attention is on the task at hand. It doesn't sound like it just to say it.....but concentrating on one thing for 5+ minutes is really hard.
If you're on a great run, but you slowly start to miss your points, don't just let it slide...it will just get worse throughout the rest of the race. If I feel myself getting sloppy, I do a quick head shake, blink a few time, breathe out hard and I'm right back in it.
The biggest thing to aviod is getting flustered. If you're re-doing the place, nothing is going to bring that back. At that point, just save the car, you're obviouesly out of the race, work on salvaging the rest of the run with the car intact.