Trying to wrap my mind around some things

I know nobody reads this blog and that's totally may fault.  I've totally ignored it basically for the past few months, and it's pretty boring without cute pictures of my kids.  So I need to sort through some stuff and I guess I'll just do it here.  If anybody reads this and has some input, please share.

My boys really just don't care about their grades.  Right now there is only one A between the 2 of them.  Some of the classes don't have grades listed, but of the ones that are, one A.  Some of the classes are hard and I get that it's harder to get a good grade there, but for the most part it's pure laziness.  Some teachers let the kids retake the daily quizzes if they don't pass them.  Some the teachers allow corrections to be made on assignments for full credit.  But do they do these things? NO.  They just don't care.  I get so frustrated when I know they did an assignment, but there is a zero listed because it didn't get turned in. I ask them everyday about their homework.  I remind them.  I sign things.  I make sure they have said work done.  It still doesn't get turned in.  I am at a loss.

Some people work outside the home.  In their jobs, they receive a paycheck for the job they do.  They receive praise from their co-workers.  They get to see the results of a job well done.

As a stay at home mom, I get lots of rewards too.  I get to see my kids learn and discover new things.  I get to see them interact with each other.  I see them help me out so much and each other too (sometimes).  These are great rewards.  But when they are failing important classes in school and not even caring, it makes me feel like I am not doing a good job.  I feel like I am failing.  I feel like I should be doing something more, but I don't know what that is.

How can I separate myself from the choices they make?  How do I let them learn from their mistakes and even let them fail?  I want them to succeed.  I want the world to see how smart they are and how amazing they are.

How do I  let this be about them and not me?  That "f" on the page is not listed under my name, but theirs. But I feel like that grade is mine.

UPDATE:
(the next morning)
I wrote this last night, very late last night.  I've had a chance to ponder, pray, and think more on it.  I wrote both boys a nice letter telling them how great they are and how proud of them I am.  Because I am.  They are awesome people, with great minds.  They also have free agency.  They get to make their own choices in life.  My job is to make sure they have a firm foundation to stand on, and to make sure they have a chance to learn.  What they do with that knowledge is up to them.  I will keep doing my best to teach them and give them opportunities.  I will help them in any way I can.  But it really is up to them to use what they learn and to be responsible.  This is the time of their lives that they have to learn and grow.  I will continue praying for them with all my heart.  I know they will be okay.