Call it an inferiority complex, a belief that my life isn't interesting as I don't do that much. But, as Adam says, it's the ordinary lives, the "random glimpses into humanity" that pique your interest, not just the grand gestures.
My favorite blogs tend to be those that are informal, unedited, and reflect the author's voice and experiences. Rarely are they those that have grandiose lives or try to make them seem so. I truly adore a personal blog.