It's a common mis-understanding... .. .. .. ..
Look at your wii to the left ( or above, depending on your orientation) of the power light. There you will find a flap that is basically the whole side of the Wii. If you open it it reveals four controller sockets and two memory card sockets. These are for GC controllers and memory cards.. .. .. .. To play GC games on your Wii you will need to spend more cash and purchase a GC memory card and controllers.. .. ..