Why do so many students grades drop so much once they enter college?

<p>My S’s experience has been the opposite: he graduated with a 3.15 weighted GPA, but got a 3.8 his first semester in college. He did go to a very challenging high school and took mostly honors and AP classes, and they had a “modular schedule” with free periods throughout the day and an open campus for upperclassmen - I guess he was better prepared for college than I thought.</p>