Courtneys adventurous spirit takes a beating in the first half of Kill The Moon. When things get real she is overwhelmed and runs for safety. She is, of course, a child and Clara takes the Doctor to task for not understanding this. He is a danger to his companions theres no getting around that. But as he points out there is danger in crossing the road. Curiosity is one of humanitys greatest strengths but it cannot be satisfied without risk. There is no guarantee any of us will wake up tomorrow. What we choose to do with the time we have is the important thing. Is it better to die at thirty after having seen the wonders of the universe or at hundred never having been farther than our own backyards? As Courtney laments, once one has picked the apple its impossible to put it back on the tree.