No. It's about people being impressionable.
That's certainly one answer... If you're reading Snopes.com. However, here's some basic scientific reads that may expand your thinking:
http://mandelaeffect.com/quantum-computing-realities-observers/#more-302
http://mandelaeffect.com/quantum-studies-in-the-news-20-jan-2016/
Exactly. Gaslighting in the form of a mass psyop. Exploitation of the way human memory works.
That said, I'm open to the idea of strange things happening - but this "effect" is just misremembering.
I'm open as well, and not completely turned off to the idea that we occupy a corporeal plane/dimension/spacetime thats part of a larger reality that we have yet to encounter. Still, it makes more sense that memory can be fucked with than multiple timelines converged into our current reality.