f: uncountable, infinite 
f: countable, finite
Etymology: The origin of this symbol and spectrum
F was at first the f of infinity, for I wanted something to reach beyond. But you can not use infinity in your daily life. I needed to show that something was countable and recountable. So, I turned infinity on its head, which has an eery resemblance (ok, ok, it looks exactly the same as) a figure 8. Thus, I could indicate that my resources, my strength, the number of coins in my pocket was very brief—very easy to count because there has been so little. But I could, with just the turning of the page, show that the possibilities were—and are--endless.
Orthography: How to remember these symbols
If you know any math, then use the side infinity sign as f. Then turn it as 8 for countable.
If you do not know math, then see the side as a toy racetrack, on the ground, going endlessly sideways between one loop and the other. But if you turn that toy racetrack up, then the number of cars that can still go up and down it are limited indeed.
Philosophy: How I use these symbols to embrace life
If I think that I have very little of something, such as time or money, then I trace the symbol up and down, almost as if tracing my fortunes (right now I am at the bottom of the eight—things will get better—right now I have some funds, I’d better save them for the trek down the eight).
If I want to think on the infinite vastness of the universe or think about many many possibilities, I trace the infinite on its side, going up above the center line of the text and below the line of the text, thinking of how endless infinity can be.