The worst part with that kind of mistakes is that you end up never knowing for sure. :)
You start with "ln -s A B" and realize you always make the mistake, so you force yourself to do the opposite of your natural instinct: "ln -s B A". It works until this becomes natural but you still think you always get it wrong, so start doing the opposite of your new natural: "ln -s A B". You'll now be very confused until you force yourself to learn it for good.
This happens to me all the time for various binary things.
You start with "ln -s A B" and realize you always make the mistake, so you force yourself to do the opposite of your natural instinct: "ln -s B A". It works until this becomes natural but you still think you always get it wrong, so start doing the opposite of your new natural: "ln -s A B". You'll now be very confused until you force yourself to learn it for good.
This happens to me all the time for various binary things.