I always knew there were several moon landings, learned that pretty early on in school. Apollo 13 was supposed to be one too, before they had the explosion.
The Jif/Jiffy thing is pretty easy to explain, as far as these things go. Jiffy is a corn muffin mix, there were commercials for it and everything and it's another thing lots of people probably saw in the pantry as a kid, right next to Jif. Memories are funny like that.