Edit a childhood photo of yourself to include a more recent photo of you in a pose that makes it look like you were part of the original scene. Pay attention to matching pose, detail, shadows, and color values to match the original. You can go back to your past, at least in your own edited photo!
Based an example of Before and After Pictures with a Twist spotted in Buzzfeed. See also more exquisite examples in Woman Photoshops Present-Day Self into Childhood Photos.