I went to a state-related school, so maintaining a high GPA was pretty easy. I don't think my grades ended up mattering much to anybody other than me after college, but at the time they helped. I was able to take advantage of some opportunities during my undergraduate years that required good grades. I got a fellowship to do undergraduate research, and a two-year full scholarship from the math department in my last couple of years. At the least, I saved a fair amount of money.
So, judging from my experience, I'd advise you to keep an eye on the current financial effects of your grades. Otherwise, I wouldn't sweat it. Unless you're planning on staying in academia, or applying to grad schools.
I do have one additional piece of advice, which you can feel free to take or not take. It makes sense for a high schooler to resent testing, since you are forced to attend. It doesn't make sense for college student, because you're there of your own free will. Saying "I hate being 'tested' like a lab rat" indicates that you're not approaching college as the voluntary experience and opportunity it is. Losing that residual resentment might help you with some of your motivation and performance issues.
Thanks for the advice. I do not resent tests by themselves. For e.g. I'm fine if you are continuously tested throughout the year. However, I have an issue with a test that is 40% of your grade, and is just 3 hours. It could render your quarters work useless if you messed up.
So, judging from my experience, I'd advise you to keep an eye on the current financial effects of your grades. Otherwise, I wouldn't sweat it. Unless you're planning on staying in academia, or applying to grad schools.
I do have one additional piece of advice, which you can feel free to take or not take. It makes sense for a high schooler to resent testing, since you are forced to attend. It doesn't make sense for college student, because you're there of your own free will. Saying "I hate being 'tested' like a lab rat" indicates that you're not approaching college as the voluntary experience and opportunity it is. Losing that residual resentment might help you with some of your motivation and performance issues.