Learning and Thinking

I have been a pharmacy technician instructor since 1981 and I love my job. I have found that it is harder to teach critical thinking skills than memorization skills. I have found that most of my students love the memorization portion of our program and are mostly dreading the critical thinking skills. Why is that? Asking a student "what would you do" seems to terrify. Our students are very conscious of patient safety but almost afraid to think "outside of the box". Any comments?