This question opened up our discussion today. We thought about how all of experiences and knowledge "stick" to our brains. We also recognized that each of us is unique in the experiences we have had. To illustrate this, we created lint-roller-sticky-brain sheets - covered with sample experiences from our own lives. Each student's sticky-brain sheet is different.
These experiences we have had make up our "background knowledge," or schema. We use schema whenever we are learning something new because our brains attempt to attach new ideas to information it has already learned. That's why activating our background or prior knowledge before learning something new is so beneficial (a great connection here today to what students did with Mrs. Rajacich in Study Skills class!).