<p>“passion” is unfortunately at times well-known to adolescents 
- adulthood would certainly make passion less likely, as we are more reasonable, even-tempered, etc, than our adolescent selves, and thus less prone to passionate attachments to peculiar subjects, activities, people, etc.
What colleges want to know is: if you’re really, really into something and give your 100%, what’s the end result? What are you capable of, preferably on your own or with your own impetus? Can you be creative, can you organize, can you mobilize…? Do you have skills beyond those revealed by your grades? Have you done the best with what you had? What distinguishes you from all other applicants?
And they also want to know: will you be an interesting person for our campus? Will you fill an institutional need? Will you bring a personal/unique perspective to class discussions? Will you enrich the lives of your peers?
So, the motivation behind ECs at “holistic”, very selective colleges, is double: to select the “best” individuals broadly defined, and to “craft” a class.</p>