Why do I live my life? Simply because I am alive. By my mere presence on this Earth I am alive. There was the longest time I wasn't living and was merely existing. Am I really past those times? Well yes probably really. There's always something more to do and more to see. Every time you think that you have done all there is to do with your life something new comes along. I live because I must. There might be someone out there who needs me, and I have to be there for them.
Maybe even somewhere out there there is someone I need.
I live really just because every fiber in my being, except for the deepest parts of my heart and mind, tell me to. To see what may come next. If it is going to be terrible then I need to witness it with my own eyes.
Back when I was suicidal what got me through the day was the thought that I would be ending my own pain, but I would be bringing pain to the few people who loved me. In the end my selflessness kept me alive.
Also I love philosophical questions like this. I'm quite good at them. Especially rhetorical ones. Nothing says "smartass" like giving a full and genuine answer to a rhetorical question
So what can you take from this? Well it appears I have a bit of a God complex but I think we all knew that one really.