First off I should note after the recent finale where Jayne revealed the seven people he had narrowed down the list to that I am assuming the writers are not going to dick us around too much and Red John is either Jayne himself, one of these seven, or a combination of these suspects.

We know Red John does not actually have psychic powers so I would like to think Jayne is finally being clever when it comes to Red John and is one step ahead of him. It would appear that the only way Red John could have predicted those seven suspects is from when Bob Kirkland had his people copy the notes from his loft.  I doubt Kirkland himself is Red John but it is obvious he is connected to Red John in some way.  I think Jayne has a plan now and knows more about who is Red John then he is letting on, leaking the info to Red John to let him feel clever and think he is still one step ahead. This would explain how he knows the seven suspects but it is still unclear about the whole "happy memory" thing but likely Jayne leaked that somehow too....

The other explanation how Red John knew the suspects and the happy memory is that Jayne is actually Red John and does not know it. Personally I really don't think this is the case but really the writers could do this if they want to be dicks...