I did not see my youngest brother for over ten years due to being kicked out by my parents. When we got back in touch eventually He told me a story about me hanging him by his feet out of a window.
My brother is completely rational (he also was never a believer) and doesn't believe in anything supernatural, however over the years he had come to believe that I had held him by his feet out of a window. When we got back in touch he asked me if I remembered doing it, I pointed out that I was about twelve at the time and that I couldn't possibly have had the strength to hold him by his feet and then haul him back inside on my own. He was so convinced by his own 'memory' of the event that he wasn't able to look at what he was claiming rationally.
Once I pointed out that I would not have been physically capable of doing what he had remembered he was fascinated that he had managed to convince himself it was a real memory.
Perhaps in your mind you have conflated your own real memory of someone having a picture of a smurf with the fairy tale smurf story so popular in JWland.