That would just tell you the size of your red slice compared to other people, and you would be discriminating in favor of things that are relevant to your life. I true perspective of how much you don't know you don't know would have to take into account the possible sum total of all knowledge; good luck with that.
Theoretically, they can also be statements that are testable in the future.
Ex: At 25C and 1atm, oxygen is a gas, not a liquid or solid. No matter how many times you test that, it will always be true; hence, it is a fact.
Of course, if you ask enough questions (How do you know it is 25C? Why are you confident that instrument is accurate? How do you establish the temperature scale in question?) the person claiming it is a fact will eventually get confused (it is was something they didn't realize they didn't know), send you off to ask someone else (if it was something they know they didn't know), or bored (if it was something they know but they are tired of answering your questions) and you will be free to think the fact wasn't really a fact after all.
Well, you just convinced me you believe that, thereby demonstrating that "b" is easier than "a". Congrats!
However, you are still wrong. At one point the US National Government spent $1/4 mil per year in attempts to convince people who had bought American-made cars that they had made a good choice. (I don't know current stats, and know that I don't know them.)
Think of it this way: If you can convince people who bought your product to feel good about their decision then they will speak well of your product to others. Reputation and word of mouth are both powerful and worth investing in.