I remember a teach in high school having us write down the steps to making a peanut butter and jelly sandwich. When I was finished the teacher asked, "What do I spread the jelly with? "A knife of course," and his response.... "What does a knife do?"
The teaching of concepts is something that I think as a teacher I try to not take for granted and do my best to constantly check for understanding in the class room. The steps of teaching using objects and breaking down their use and characteristics to their basic form.