In the operating room, Mitty calmly saves the life of a patient. First, he repairs a complex machine by substituting his pen for a faulty piston. Then, when the patient takes a turn for the worse, Mitty performs a life-saving operation.
In the parking lot, Mitty is neither calm nor efficient. First, he nearly smashes into another car. When the lot attendant yells at him, Mitty becomes nervous and forgets to hand over his keys after he gets out of his car.
This is Walter Mitty. In real life, he is bumbling, inefficient and easily intimidated. In his dream life, he is calm, daring, and extraordinarily skilled.