The process of addressing a child's prior knowledge to make connections to what is being taught is extremely important as addressed in the story Fish is Fish. By listening to the frog's description of the animals, birds, and humans that he had seen, and not having a frame of reference, the fish constructed its interpretation based on its current knowledge. To the fish, everything the frog described had a fish-like form with the proper alterations according to the descriptions - birds were fish with wings, cows were fish with udders, and humans were fish who walked on their tailfins. This is exactly what students bring to school, their preconceived notions, and misconceptions about various issues that if not corrected by the teacher during the process of learning, will later lead to learning impediments.
This brings to mind a kindergarten classroom that I observed where the teacher introduced the word triangle and asked the students to draw a picture of what they thought a triangle looked like. She stated that before she showed them a picture, she wanted to know just how much they knew about triangles. The majority of the class knew their shapes and quickly drew a triangle. Some, not knowing what it looked liked drew their concept of what the word meant, but there was one boy that was taking an inordinate amount of time with his picture. When I walked over and looked at his paper, he had a crude drawing of what appeared to be a hand next to a triangle with a circle on top and what looked like the number 1 at the base of the triangle, with another hand next to it. Explaining his picture he stated that he played the triangle at church and the picture was one of his hands holding the top of the triangle while hitting it with the stick in his other hand. This showed the connection that this student was making which was far beyond basic shapes, based on his background. The teacher hearing the story, quickly incorporated this into her lesson.