I was in a similar situation to yours. K-12 was easy enough that I did well on test and assignments without ever having to develop good study skills.
So, naturally, when I got to college, I was woefully unprepared to cope. I was at a small institution where 90% of the student body was an academic overachiever in high school, so there were few enough students like me that the university didn’t have a dedicated tutoring place where one could pick up some study skills. Combine that with possible undiagnosed ADD and mental health problems, and it’s a wonder I managed to graduate.
“You wouldn’t download a car, would you?”
“Nah, I’m too busy downloading cum.”