Many years ago I was given the opportunity to take my new 35mm camera into the depths of a turn-of-the-20th-century power generating station in Niagara Falls to take some pictures for another portfolio. Unfortunately, I really didn't know what I was doing, and out of a few rolls of film, I got just a few acceptable images.
Years later, however, I was able to scan those "failed" images and "salvage" the interesting bits...