Mentally strong running

I hear of some people who train MAFF, which is a training style of running slower all the time, and then when they race they just nail it because, they say, they don't forget how to run fast. There are other training plans out there too that are just unconventional but the work.

Is that because the training plans are better or because the trainees believe the plans to work? Do I go at my pace because I see what other people do and copy them (physical)? I wonder what pace I would do in a race if I'd never done one before and not seen anyone, other than me, run before (mental)?

I'm doing a 100k race in May and already I've looked at others and compared to find out what pace I should go at. Will this mentally cap what I might be capable of, who knows.

I think the great Steve Prefontane aka Pre never used to let other runners dictate his pace. He was A mentally strong runner.