How important it is to relate what we are teaching to something the learner already knows or has experienced. If we take too big a jump then we will lose them. Petty (1998;40) tells you that "students must see the tasks you set as being both achievable and substantial" and to remember that "it is the students' perceptions of the difficulty of the tasks which count - not yours.". This is why we need to know our students and accept that they are all different. If we embrace this then we know that everyone will have some experience to contribute in the mix of whatever we are discussing or learning. It means as teachers we must be prepared to listen and embrace what is contributed. At the same time we need to be creative in how we can relate complex subjects back to something relevant to the student ... so sometimes it is good to ask them what they know. When we ask we may well find that they do indeed come up with something ... we need to be ready for any answers as soon as we open something up to the class and be ready to facilitate.
How we ask and the language we use matters as well. We must also be prepared for students to know more than us and to embrace that as well. If we trust our students and embrace their knowledge we can develop confidence and enquiry, both important traits for students to promote motivation intrinsically so so develop a "better" student. Students may not come with that kind of motivation, but as teachers we can help create it