Watching the rest of the anime, the girl (Haruhi) slowly looks at the world different. She finds a reason to continue. And through the entire last episodes, she always has a smile on her face. She changed.
Why? Because everyone purpose in life is, as someone said earlier, fun. The quote took place about half way through the series. After that, she found her friends, and the main character, Kyoto, her purpose. She lived with it, and had fun.
I should kill myself for letting an anime get to me, however, there is truth in this. Last night, I had a grade school "reunion." Before that, the only thing I could think of was that quote, however, once I was around my friends. I never thought of the quote. I figure, the purpose of life, is friendship.
As I said, i should probably kill myself for letting an anime get to me, but it probably was a good idea to bring up, and think about. Its made my view different on this world. A better view.
Ahh well, some questions should remain unanswered.