Good checklist hygiene says don't repeat yourself, because it trains skimming. That rule has exactly one exception, and it's the important one: the killer items. For those, repeating yourself is the whole point.
A pilot once tried to take off without the 10 degrees of flaps his airplane needs. Now "check flaps 10°" shows up in a few places in his flow: Departure Preparation, the lineup, the memorized sweep. If one catch fails, the next one gets it. He'd rather be annoyed three times than wrong once.