"Adolescent" is a fancy word for Teenager, and as you know a lot of things are happening to you during Middle and High School. I've put up some information that might help you understand some of those things.
Cognitive Development - How our thinking develops, including how we learn
Emotional Development - How our feelings develop
Social Development - How our interactions with others change
Schools and Teachers - How we can best motivate students to learn
Unless otherwise noted, all information sourced from readings provided by Professor Maria Castiglioni for EDSE 0502A "Adolescent Development and Learning in Urban Context" Works Cited available upon request.