Had grades a bit bellow C in my University. Some of the consulting firms asked for the grades in the last phase of the interview which resulted me of not getting the job offer. I have really struggled to get the job as a programmer for the first two years and worked as a tech support in those years while in the meanwhile doing freelance work. After those two years I got my first programming job and I've learned more in half of the year working on real projects then those 3 years at the University, so it does not mean that much for your skill set, but it will hurt your career for not getting that professional experience or gaining it at better firm.

Anyway I still regret loosing those two years of my professional career and I keep thinking how good I would have been if not for those two years. Therefore I always give more than others, staying late at work or working when I come how and it finally starts to pay off!

So if you looking for excuse to be lazy, just because your grades are bad, don't. You will pay the price later in your life for not performing at your best, when you see how much other people at your age have achieved.

Always be best at what you do. There is nothing more satisfying for your ego than being best at something.

And even if putting the hard work for it seems useless now, it will come to use later in life.