That sounds familiar. I knew lots of folks whose motivation was highest at the start of college and then the grind started wearing on them by the end.
My lopsided experience was mostly due to undiagnosed ADHD. “Gifted” when young, distracted by girls and unknown ADHD as a teen, then finally diagnosed at 20 and my grades came back around.
I really didn’t expect this comment section to make me actually want to try it…