This morning, while writing in my journal, I found myself wondering if pencil sharpeners are allowed on airplanes. This is precisely the sort of question that the human mind can only ponder because the rules for what one can take onto airplanes are arbitrary and subject to change at any time.
The arcane rules governing air travel are excellent conditioning for an even more authoritarian regime. Because some business folks travel frequently, all of the rules are enforced not just by government agents but also by fellow travelers. The whole thing carries with it a tone very much akin to “Why did you try to bring x on a plane? Everyone knows x is forbidden," and so you conform because, yes, you don't want to go to jail but also because you can't go around not knowing things that everyone knows.
Incidentally, the answer is yes. You can travel with pencil sharpeners in your carry-on luggage.