It's always worth going back to the basic fundamental topic of all life and having a good old think about it - existence.
Because really, whether people realise it or not, their core beliefs about what "existence" is, and what it's for, and why it's there, really comes out in their life, be it consciously or subconsciously. Except most people gave up thinking about it due to the complexity of it. But it's worth digging for truths!
What are your theories?