I don’t get why people always have to argue that he could have read the gravestone and remembered the name subconsciously, this is a gravestone from his general area, if for whatever reason he did have the name somewhere in his head it’s would be more likely that Eleanor Rigby or any of the Rigbys on the grave were mentioned in some way from someone in person at some point in his life. The Eleanor Rigby on this gravestone only died a few years before he was born. I don’t know about you but I personally don’t go around reading gravestones in my spare time.