Perfection

Is it right to strive for perfection? I've recently been wondering if it is actually pointless to reach for what you know is unattainable. We hear all the time how nobody is perfect and everyone makes mistakes. Why then, do we do everything in our power to be perfect? I understand the need to try to improve yourself and do your best, but is there ever a time where it is okay to just sit back and be happy? Would life be more enjoyable if you were just content with yourself for a while? Is it okay to 'take a break' from being the best you can be? I'm not saying you should slack off, but everyone knows where they are comfortable and how far they go before pushing themselves off the edge. Should we always be trying to make that line further and further?
We all have our strong points in school and specific talents. Is it acceptable to just focus on one of them? What if I want to really focus on history, and I'm no good at science? Is it okay for me to put all of my efforts toward history, and possibly slip a bit in science? Or do you have to be smart enough to know how much you devote to one subject without falling behind in another? And what if you don't want to excel as far ahead as others may expect you to? Like taking AP classes as apposed to regular classes. You may be perfectly comfortable in the regular class. It may even be a bit easy for you. Is it okay to rest and take that? Or do you have to push yourself? What if you know you could achieve good grades in the higher classes but you don't want to work that hard? Would that be considered lazy? Or would you just be taking a break?
I don't believe perfect is something I will ever be. I know I won't ever be close to it. Sometimes I wonder if it is actually worth it to try to be.