Although it might sound a bit tedious, it is important to listen when someone tells you a personal story. Although I've never recorded these stories in a journal, you may find it necessary to aid your memory. I actually like the way my brain has mashed the thousands of stories I've heard into a glorious mess when I'm ready to use them.
Collect the trivial stories of others. You cannot rely on your experiences alone to provide sufficient grist for a novel. To create a remarkable work you must sprinkle the small stories of others throughout. In my first novel, Toil Under the Sun, I included a variation of the story of a man who had served in the First Marine Division during the Korean War. He had evidently shoved a branch that looked like a shriveled hand up his sleeve and had sent a photo of the unfortunate spectacle to his mother. It only took him a few seconds to tell the story, but it provided me with over two pages of quirky material.