it isnt that you know how to spell, it is that you know how to memorise and remember what you memorised. so basically you can remember what you memorised.
the english language is so screwed up that there is no real system to it. too many exeptions, and exeptions to exeptions. as if each word has its own rules and system.
so congrats on remebering what you memorised.
oh and you should learrn martial arts, because spelling bee winners are beaten up by bullies and such.