Asking why in any meaningful way is a more complex question than how. If we ask why a person grew up to be the way they are, they should be willing to honestly look at the how of it. Regarding the why and how we get here, I look at things in terms of circumstances that already happened. It's not as exciting at first as claiming that we are gods gift to the planet, souls incarnating into matter to evolve or that aliens created us as an experiment. But if you think about it, the events that have happened for us to be alive or mind-boggling. Our parents had to meet, probably even eating certain foods or being conceived at a certain time, have sex and we won out of all the genetic possibilities to make us possible. We had to survive to be born, though thanks to modern science that's much easier than it used to.
Before that our ancestors survived many almost impossible circumstances like wars, slavery, famine, terrible winters through grit, willpower and luck. And how long has that had to continue for us to be here? Uncountable generations of humans and other ancestors before that... finally examining it, it's a greater story the deeper we look into it.
Not much changed after I stopped being atheist in that regard and I don't think it ever will. I still don't know why or how, only some of the circumstances that lead to what is now. I'm more interested in what exists now, though history and evolution is fascinating.