This is what people expect from you before college.
You start preparing for the future as soon as you're born. some parents even start planning before.
Throughout your school years you learn about college and your teachers prepare you for it.
Once you get to the highschool it's crunch time. You start taking your SAT and start applying to colleges.
Although your school years probably influence you the most about college readiness; friends, family, and the media definitely play a big role too.