Lets be blunt: if you are going to sit around and wait for greatness to find you then you are wasting time. I've met quite a few people who seem content to just wait for someone else to find them and recognize their "obvious greatness." It's as though you're sitting in the pitch black deep within a cave somewhere and just expecting someone to happen upon you. It's a ridiculous expectation, and one that will in all likelihood get you absolutely no where. Something that my teachers will admit to often is that you frankly learn about 10% of what you need to know actually in school. This isn't to discount what you learn in school, because frankly that 10% is important. School can't possibly teach you to handle every possible situation you will ever encounter, but giving you a torch to help illuminate the way in the first place is a huge help.
(Image from: The Adventures of the Princess and Mr. Whiffle the Dark of Deep Below)
(Seriously NOT A KIDS BOOK)
The rest is learned through experience, and though you will never know absolutely everything its always good to have a start. For instance, as you start to develop you're sure to run into issues along the way. In the cave these are chasms you either need to cross or explore their depths. The torch won't help you much with you get to the chasm in the cave but at least you can see the chasm right? That way when you actually encounter it you can actually for some kind of plan: maybe you need to find a rope, maybe there's another path, maybe something new is required, or perhaps it just can't be dealt with given the tools available. The last one might sound like a complete loss but in truth what you've done is not wasting a significant amount of time and resources to a lost cause. Make no mistake though, you aren't about to just stumble on greatness either. Everything you have you will work for, and what searching the cavern will afford you is knowledge and experience.
One of the other bloggers on this site, Scott Fronapel, wrote a great article Woah There Cowboy - Game Development Precautions. He goes over a few things that beginning game developers should know, with perhaps the biggest being Scope. I've talked about this previously in my own posts and frankly it can't be stressed enough!
Testing your limits is important, because it teaches you to be better. You should ALWAYS be working to be better whether you're a student or a AAA developer period. However, it's always important to know your limits in the first place so you don't find yourself lost in dark.