This is gonna sound really bad, but I'm an anonymous dude on the internet so here goes. Didn't work hard in HS at all. Seriously, slept through all my classes (teachers stop trying to wake you after the first quarter) cause I thought I was some hotshot genius (spoiler: I'm not). Well HS was "easy mode" so I still did well in classes, and did real well on the SAT (2370 ~= 35 ACT). I got into a very competitive school, but the girl I tutored daily in AP chem/physics ended up as valedictorian with a scholarship to Stanford (first person from my HS even accepted there in decades too). So at the end of HS, I was basically you (though you may be a more respectable person than I was).
So I got to my new school and everyone is all elitist and pretentious and I'm just some kid from public school who never gave two s***s about anything. I decided within the first couple weeks, with all these kids talking about grades and being obnoxious about it, that I wasn't going to let some kids who were "dumber than me" (a dumb viewpoint in itself) become more successful than me. I literally just let pride take over and studied hard for 4 years. Yup, I rode my stubborn pride to a great GPA in college, which is ironically not my proudest admission, but you have to find that thing that unleashes your motivation Midwest. It's not always pretty, but that's because it has to be honest. Happy, satisfied people don't push themselves as hard as it takes to get a 4.0 without something to prove.