My marks really haven't made that much of an impact on how my life is going. I don't think doing better would change where I am, but doing worse may of... you need a good GPA for certain colleges... but I go to community college, so...
off topic...
But if I would of acted differently in HS or had different friends, my life would be far different.
Don't try to be something you're not... don't try too hard to fit in... I made that mistake. It took till 11th grade to realize that what others thought of me didn't matter. And just being myself and doing what I wanted and being friends with whoever made the rest of HS much more fun