There is a unique instinct present in humans. The desire to know more than you know now. To venture into the void uncertain of where it will lead you or whether you'll live through it. This innate hunger, to look up at a mountain and yearn to know what is on the other side, has been the driving force for human expansion, knowledge, and understanding for all of time. It has caused humans to become the most widespread and dominant animal in our current understanding of the universe, and it is this instinct that will allow you to achieve all of your goals in life.
Unfortunately, just as in our own lives, there will always be society, others who've come before you, or your closest loved ones who demand some “mountain” cannot be conquered. If you let them convince you, they'll always be right.
Do not fear standing at the base of an unsurmountable obstacle. Yearn to know what is on the other side.