books
I mostly read "popular science" (that is how Google puts it) books.
I loved reading not-in-syllabus science books till 10th grade, but then high school and JEE (Joint Entrance Examination) happened.
For people not from India, around 99% of the colleges in India accept students solely based on the marks they score in some particular, unnecessary, over-complicated, and over-competitive exam. Students are expected to give up their hobbies and interests and prepare for these exams (along with their usual high school studies).
Now that I am in college, I plan to start reading again!