Rightly or wrongly, Gerrard seems to have spent the entire time he worked with Benitez believing that he wasn't liked on a personal level.
Rafa has obviously denied that this is the case, and maybe it is just Stevie's own insecurity and paranoia at work.
But obviously it would colour his perception of Benitez, and affect his relationship with him. Nobody feels particularly warm towards someone who they believe doesn't like them.
Hopefully, after Rafa's comments on the matter, Gerrard realises his mistake and his perceptions will change.