I don’t think the question is “why do you philosophize?” as if we philosophers are the only ones who do it. Everyone philosophizes, i.e. asks the big questions, without perhaps knowing that that IS philosophy. So the question is really “why does humanity philosophize?” Is it a feature of consciousness or of having a complex and developed frontal lobe? Is it what makes humans humans, as opposed to other animals? In other words, is that what makes us human?