Recently, a friend told me that she "lives in the moment". By this she means she focuses on the present—what's happening now. I took it as the foundation of her general take on life. I've heard this from a lot of people—this kind of foundation; I would assume it's a popular way to live one's life. I don't live in the moment and I don't think anyone else should either.
I like to think ahead. I envision shit. I like reflecting. Conversely to my friend, I live in all moments. Of course I leave room for spontaneity, but generally I have a plan. For me, "living in the moment" means living with tunnel vision. Imagine looking through a telescope onto a lake and spying a speed boat. You follow it along the water, skidding and bouncing. It's quite exhilarating. But you're missing the rest of the lake. In fact, you might forget that it's a lake that the boat is on because your looking at it through a telescope. That's what I imagine life to be like by living "in the moment". It's fun but the actual scope of experience is quite limited and therefore missed or forgotten.
This is exactly what Hemingway was talking about in his short story Snows of Kilimanjaro. It was about a writer who lives a decadent life and never actually wrote anything down. And in the final moments of his life, he realizes that he has nothing to show for his exceptional journey.
I imagine that people who live in the moment are always comfortable. While that's not bad at all, it can lead to complacency. I can't allow that in my life and I wouldn't want that to befall anyone else. I just can't imagine living a fulfilling life by "living in the moment". The character in Hemingway's story was a writer who didn't actually write. I see that as a metaphor for someone who didn't actually live, or at least didn't live up to any expectations.