I. Failure to discriminate. That's whenever you see different things as the same thing. You can bet your last dime that I'm sitting there in the darkness, sharpening a small throwing knife every single time you do it. And one day, "when you least expect it" as the moron expression goes, groundless as it is because you totally should fucking expect it, one day "as far away as possible" that blade will plunge into your soft tissue.
PS. I don't mind waiting.
II. Spurious discrimination. That'd be whenever you see the same thing as different things. It's a common mistake of children, imagining the flying bug and the resting bug are different items, or of very simple minded people, going into a room with an elephant and coming out with "contradictory" stories of legs and trunks and whatnot. This almost never pisses me off by itself, but I also tend to readily recognize it in practice and consequently treat the other party to a tall plate of derision. They generally react idiotically, which generally thickens the derision into disdain, and in short order forces them into I above. All in all, a situation best avoided (though slavery provides some healthy recovery mechanisms).
III. Dynamic blindness. When two objects correctly perceived also share a relationship that is not perceived. This is the general state of ignorance, and the trampoline starting most educative discussions in my harem. It doesn't piss me off noticeably, though there's a particular slide that works as follows : failure to perceive a relationship prompts me to introduce a different set of elements that find themselves in the same relationship, to instruct by comparison. If the other party further lacks familiarity with the other set, I'm going to try more and more sets until the set of usable sets is exhausted, at which point I will say something more or less in the vein of "well, you're too ignorant to be taught this right now", which butthurts the (extremely ambitious, by the way, let alone extremely intelligent) girls that kneel for me something fierce. Fortunately it can be overcome with training & experience, but it's always and evermore an obnoxious thing to hear, I'm told.
If on the other hand the other party shows familiarity with the other set but nevertheless also fails to perceive the relationship in question I'ma go into mental health diagnosis mode, which can be emotionally traumatic (in the sense that it universally is, for retards).
This whole thing wouldn't figure here at all, except that stung morons tend to go to I above, and then...
IV. Hallucination. When a relationship is perceived between two objects correctly perceived that I'm not aware of. This mode is first and foremost my mode of learning, "wait, that hottie in Bound is the sister of that other hottie in the Psycho remake ?!" but it's also the mode of coffin liners and assorted mystagogy. This mildly pisses me off if I discover myself trapped in the situation whereby I thought I was talking to another person, but the actual substance on the other end is more in the vein of Eliza, and the responses to my lines came not out of an interpretation of their meaning but out of internal processes fundamentally meaningless. Nevertheless, it is an intellectual sort of displeasure, and doesn't generally produce rage, at most can climb up to nausea.
I. though, that can produce fucking rage. So in practical terms : think that discrimination is your only ticket to survival, and understand that "we don't discriminate here" is how "here" gets the napalm treatment.