One of my favorite sections of any vintage store is the postcards/photo sections. You can usually find used ones that are full of love, and if you are lucky, draaamaaaaa. Oh, the things people wrote to each other about is so silly sometimes. A real sign of the times. You can be entertained for hours. Sometimes there are multiple written by the same people, so you really get to know the skinny on what their lives were like. You do need to know how to read cursive though, because every single letter is in the most insane handwriting you've ever seen.
