It doesn't matter what your mountain is--just start putting one foot in front of the other and get yourself to the top. Don't stop. Once you stop, it's hard to start again. Motivation is often a fleeting concept, and if you allow yourself to stop walking forward, you might just decide it's much easier to turn around and head back to where you started--to walk away from the mountain and leave it for someone else to climb and conquer.
Maybe your mountain is a paper for a class that requires copious amounts of research and annotation. Perhaps your mountain is talking to a person with whom you've had a falling out. Maybe you haven't spoken with them in days, weeks or even months, but there is no time like the present to try and repair what is broken, especially when it comes to relationships. Maybe your mountain is a change in careers. Yes, it's tough. And yes, it's scary. It's unknown territory, and there is that thought of failure that lurks in the back of your mind, but ignore that thought. Go for the career change, and throw yourself into your new work, learning everything you can so that you guarantee yourself success.
Maybe your mountain is big, or maybe it's small. No matter the size, it's important to keep your eyes on the goal. Push yourself, because even though it may hurt, even though you might face some obstacles and challenges along the way, and even though there may be no one there to pick you back up if you stumble, once you reach your goal, the mountain seems a lot smaller and much less daunting than when you started. Looking at the world from the top is exhilarating, inspiring, breathtaking, and awesome, and you can know that YOU DID IT.