A Good Day Turned Bad

I've been thinking about this...

Would it not be more likely that my gas cap failed in some way. Maybe old gasket or something, that allowed fuel to escape?

Am I to believe that everybody in the 60's and 70's, that lived south of Kansas either never had a full tank of gas during the summer or else had gasoline all over their driveways and garages? Due to heat expansion of the fuel? Seems crazy to me.