You ask, what is the meaning of life? You do so because you can. Your inclination and ability to ask this question are incidental to the evolution of predictive mental models. These models emulate and predict the specific physical aspects of reality that have determined survival and passage of genetic information from and between species over 3.8 billion of years.

The fact that you can ask this question is an offshoot of your brain's ability to model and predict a reality without requiring sensory input or motor output. Your brain can now ruminate freely and endlessly. The urge we have to ask, "what is the meaning of life", is linked with our nature of being threat detectors. We have evolved because we detect threats and respond to them, all species do. The lack of sensory awareness to the neuronal activity that generates predictive mental models, creates a void, and becomes a threat in itself. Where are these endless thoughts coming from?