What is one question you want to ask someone but you know you'll never get the chance to?

I would love to ask my great-grandparents what motivated them to migrate all the way to Bakersfield, CA, which was nothing much more than a railhead after the Great Chicago Fire burned them out to start what we would call a brew pub today when they had no experience in brewing or running a bar. The political climate and impending Franco-Prussian war make it pretty clear why they left what is now part of Germany to immigrate to the U.S., and Chicago was their logical landing place since it was the furniture making center for the entire West at the time and employed a huge number of German immigrant woodworkers, which was my grandfather's trade. And desiring to leave Chicago after the big fire is understandable, but such drastic life changes/gambles with three young infants in tow makes one wonder what the motivation was.