That is the question, isn’t it?
It’s a pretty fundamental one. If you answer no to that one, the rest of your flow chart doesn’t mean much. At least, not in any way that us alive in this cosmos can register.
Do I believe in an afterlife? I strongly suspect that there are links with our cosmos/universe that we don’t entirely get. Does that mean that our souls continue on in a recognizable form, that we ourselves recognize, after death? I would really like to think so, although of course it seems pretty far fetched at first. There are some reasons to believe that the universe is not randomly created–intelligent design people aren’t entirely evidenceless; and that leads me to hope that, somehow, our universe is a birthing place for new ‘gods’, that is, souls/creatures which eventually have an existence/life beyond our universe; or which can travel through it and spacetime. If there is a god/gods, then they obviously want us to do things mostly ourselves. But we’ve said this a bit before. And I would go so far as to say that the theologians at work today have come up with some pretty interesting stories, which do engender hope; I am talking partly about John Polkinghorne, and Alister McGrath, and Thomas Torrence. These latter make a case for a specifically Christian theology, but again, this need not be incompatible with other theologies entirely.
Of course, our current state of scientific knowledge would tell us that indeed life is meaningless; we are manifestations of DNA wanting to reproduce ourselves; we have no more purpose than cancer cells, which mindlessly propagate (and then die) as long as we are in a situation where we are not annihilated entirely.
And so many intelligent people have been, in the twentieth and twenty-first centuries, quite cynical as to the ‘meaning of life.’ They point to the billions on the planet, the existence of toil, suffering, filth, pain, loneliness, debility, ageing, corruption, cruelty in the lives of so many. The internet is full of people copulating; cities are full of horrible buildings; television and movies are full of gore and torture. Freud was right: we are bestial, murderous animals.
So why bother? If we’re, as a doctor friend pointed out, about 15 cents worth of chemicals, why do it?