To return to the earlier objection, 1 + 1 = 2 without a doubt, but this truth is a simple fact, and we only get a part of the picture unless we ask who asserts it and why. Why would a mathematician devote his entire life to the pursuit of such truths? What does that say about the mathematician? What does it then say about the truths? What wills are at play, what will is dominant in the pursuit of mathematics? These are the questions that interest Nietzsche, as a philosopher of the will, and not of facts and things. The "truths" of philosophers are expressions of their wills and not simple facts. A particular perspective taken on the truth is evidence for a particular will claiming dominance.
One of Nietzsche's pet peeves is the influence that grammar, and particularly the subject-predicate form, has upon philosophy. For instance, Nietzsche accuses us of misunderstanding "I think" as implying that there is an "I" which is a distinct entity, and thinking, which is an action undertaken by the "I." First of all, as Nietzsche explains, this "I" only appears as a stable thing on the surface, but it is in essence a complex of competing wills. Further, he suggests, thoughts come to us: we don't create them. While it is impossible to find a satisfactory expression in language, we might be better off substituting for "I think" the less simple sentence: "the will to think became dominant over other wills at such-and-such place and time."