That said, nothing pulls a reader from a story faster than when characters are discussing something they should already know.
"Your sister turned eight this year."
"We just came from that store."
"You stopped at the bathroom before going inside."
Think about the conversations you share with friends and family.
There's a big difference between a discussion that begins with "Remember when. . . ." and uses a mix of dialogue and exposition to present something that previously happened, and imparting information through conversation that the character should already know.
The latter is nearly as bad as tapping your reader on the shoulder and saying: "Here. This is for you."
Always read your dialogue out loud. If it sounds the tiniest bit contrived or obvious, fix it.
(and always) Be Brilliant!
~Katie~