It doesn't really make sense. Given we use a left-to-right and up-to-down, \ can be seen slashing forward in writing direction, starting from the top, and / bac

It doesn't really make sense. Given we use a left-to-right and up-to-down, \ can be seen slashing forward in writing direction, starting from the top, and / backward. Upslash / and downslash \ would make more sense, but this is what we have. My mnemonic is that forward and back are the opposite of what makes sense.