seems like a pretty natural , common thing. untill you start looking closer, If you rub your socks on carpet you creat a static electrical carge and if you touch something that is grounded there is a small spark, Well what makes the spark that can travel 100s of miles through atmosphere? It can not be just static electricity.
Heres a web site that will give you a starting point for defining just what a lightning bolt is and where it came from.
Most people have already made up there mind to what lightning is already so, my going on here would be pointless, read the web site first and those with an open mind continue the conversation.
Ron
http://elf.gi.alaska.edu/