Do you guys remember Sophie Miller....? 

Jane told to Lisbon alone that she (sophie) helped him after the death of his wife and daughter.

I strongly think that Lisbon is accomplice to RJ.. 

Lisbon passed on the info about sophie to RJ...RJ wud ve easily got all the happy memories from her using his skills....and that is why RJ came to know about Jane's happy memories...

End of story....