When Walter White punches the paper towel holder in frustration, it's a clear sign that he's struggling to maintain his composure. After all, Walter is a man who is used to being in control. He's a successful businessman and chemist, and he prides himself on being able to keep calm under pressure. But as his world starts to unravel - first with his diagnosis of cancer, and then with the criminal activities he becomes involved in - Walter finds himself increasingly unable to cope. The paper towel holder incident is just one small example of how Walter is slowly losing touch with reality.