If I had to guess, your brain informed you that the distinction is "obvious" between things like night and day, and so you replied as if
@Audie's post was bound to be seen by everyone as ridiculous. Well... I agree with her wholeheartedly. For example in each case:
"Liberal and conservative": A single person may hold the (traditionally) more conservative view about one topic, and yet be "liberal" (again, traditionally speaking) on just about every other relevant topic. You do understand WHY I needed to include the qualifier "traditionally" when invoking the words "liberal" and "conservative," don't you? The lines are blurry, regardless. Give 10 people a scenario and ask them what "a liberal" would think of the scenario and then what "a conservative" would think. You think you're going to get the same (or even correlating) answers from everyone?
"Night and day": The Earth is a sphere, and the spinning of it causes a large portion to be in the light of the sun, and a large portion to be in shadow throughout each full revolution (1 day), and on the fringes it is what? Dusk? Dawn? Is that more day? More night? Not to mention it can simultaneously be night in one part of the world and day in another. You can even just stop and think about the fact that we use the word "day" to refer to both the "light" portion of a full revolution and the full revolution itself (
both night
and day as one unit).
"Large and small": When, exactly does something become "large?" At what size is a given thing "large?" If you have three cups, one 2 oz., one 8 oz. and one 10 oz., then the "2 oz." one is "small," and the "10 oz." one is "large" right? But what if we change the line up to include the same 10 oz. cup from before, then a 16 oz. cup and finally a 20 oz. cup? Suddenly the "large" size from a moment ago is now "small." Isn't that just plain WEIRD?!
All of these things contain a level of subjectivity. Subjectivity implies that one is hard-pressed to draw hard lines to represent these things.
I believe your post was the one that was "rubbish" - and it should probably be deleted even though it wasn't the profane one you implied you felt inclined to write.