Final answer:
Mari is certain she bought a movie ticket due to 'absentmindedness', a common memory lapse that occurs during routine tasks when attention is elsewhere. Her implicit memory gives her certainty without explicit recall.
Step-by-step explanation:
Mari is certain she bought a movie ticket, despite not remembering the act of payment, due to a concept in psychology known as absentmindedness. Absentmindedness is a type of memory lapse that occurs when one's attention is diverted while performing automatic, routine tasks. Mari's confidence in having purchased the ticket before seeing the movie is a result of her implicit memory, allowing for certainty in the action's completion despite a lack of explicit recall.
This psychology phenomenon is a common experience and often occurs when individuals multitask or are preoccupied with different thoughts. Routine actions like buying a movie ticket can be completed without full conscious awareness, resulting in an absence of detailed memory but the overall task still being accomplished.