Wait, what?

I've been wondering to what extent is a limit valid? I mean, I know that sometimes we just can't go anymore, or can't progress anymore, but as far as I've seen, that's all it is. And, I mean, the more you hit that limit, the farther and farther the limit gets. It kind of gets me thinking. How can there be limits if we push them all the time? I've skated to the point where I couldn't walk, I've run to the point where I couldn't stand, I sang until I could no longer speak, I played until my fingers bled, and I've written until I had nothing left to write. But, since I'm pushing the limit, how is it a limit? I thought limits were definite. I view everything as a marker to see how far I can get. It's not a limit, but a way to see how far you've come. 

And, on that thought, why do we feel the need to keep going? What motivates us? Is it the thought that we can get better and better? Is it because we feel obligated to, or are we just searching for answers? I have yet to understand why I don't just stop running in the middle of that hard-ass practice, why I don't stop trying that one trick, why I don't give up on singing, why I don't give up on playing, why I don't give up on writing, or why I don't give up on growing. I seem to be so obsessed with becoming a better person, and one step closer to being a man, and for what? Why do I feel the need to do these things? Why don't I have the audacity to just "hit it and quit it"? Why am I such a sensitive person? Why do people like me exist? Even now, there seems to be no limit to my questions, and I'm just curious about everything. I may not have the answers, but I question the value of some of them. Why do I need answers? I'm not confused, down, or anything bad, for that matter; I'm just curious. 

Limits, motivation, purpose. What does it all mean? Even if we figured out all the answers, we would still be trying to search for something more. It's in our nature, but at that point, what would we do with ourselves? We'd probably hide all the secrets to life and happiness for future generations of mankind to ponder. 

I'm an open book, but I need you guys to help me write my story.