When my husband Sean was in college, he worked part time for the Climate Change Institute at the University of Maine, digitizing weather reports from the 19th century. These reports were daily accounts written by average people who went outside and wrote down what they observed. At the time, their work might not have seemed critically important to them, but in a university department where irreplaceable ice core samples were kept in a freezer never permitted to go without power, these humble, daily weather reports contributed fundamental insights about the history of Maine's climate.
Let me tell you another story. The Memorial University of Newfoundland Folklore and Language Archive houses over sixty years of Newfoundland folklore including fairy and phantom ship encounters, recipes for food and medicine, boat-building techniques, regional history, and many other kinds of knowledge. Most of this material was collected by students in folklore classes who went home and spoke to their families, friends, and communities about the topics assigned to them, but I've utilized MUNFLA's holdings to learn and write about folklore genres in general. Now I tell my own research participants that their interviews, which will eventually be housed at the archive, may offer insights to future scholars that neither of us can presently imagine.