What is the greatest mystery facing humankind?

What is the greatest mystery facing humankind?
What are the top 100 greatest mysteries facing humankind?
Do these mysteries have any baring on the quality of life for people?
Will there ever be an end to mystery?
Do the questions of philosophers make any difference?
Can the questions of philosophers be made to serve real human needs and desires?
Are some questions by virtue of their nature unanswerable?
Is there a set of questions that shape my life?
What is the set of questions that shape my life?
What is the set of questions that shape your life?
Could I get to choose these questions for myself?