TOK teaches you how to think. You don't have to know anything in particular to be good at TOK.

TOK students are always asking "How do you know that?" By the end of your TOK course, you should understand that knowledge is rarely as certain as it first seems, and that we come to know things in a variety of ways – the sheer number of which might surprise you.

Answering knowledge questions – a process which always begins with the further question "How do you know that?" – should turn you into a reflective, analytical student who takes nothing for granted.