What is the most interesting aspect of experimental psychology?

Psychology has been defined in multiple ways by different psychologists. Psychology is an excessively diverse field. 

The term 'psychology' originated from 2 Greek words "psyche" and "logos". The word "psyche" means soul and the word "logos" means knowledge, so psychology is the study of the soul. Psychologists however favored using the word mind instead of soul. The most popular definition of psychology is that psychology is the science or  study of behavior and mental processes. 

There are several subfields of psychology which includes clinical psychology, counseling psychology, developmental psychology, experimental psychology, educational psychology, cognitive psychology, social psychology etc.