However, inspecting your profile I can guess what they were.
The nice answer is for an answer with score 10. Your "why are so few oprations arity bigger than 2" is at 10, and in your rep history one can see that there was a recent vote on it. So this might well be it.
The necromancer is for an answer with score 5 and the answer was given long (dont know the precis time, but is documented somewhere) after the question was asked.
One of your answers that could qualify that are at exactly 5 is the "messy proofs" one (but there are more at 5 and I did not check all for nec. eligibilty); and this question was bumped recently, so that a recent vote seems all the more likely. (This'd be invisible in the rep history due to CW mode.)
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