The reason for monkey brains is due to conflicting strategies.
If I follow the phases of reconciliation then I want to get rid of negative feelings that my W has of me. Therefore, I would recognize her b-day with the email and still give her access to my condo mailbox (she still has a key).
However, if I follow letting them go and detachment and reading past actions from my W. Then I would not acknowledge my W's b-day, (why does she care if I say "Happy b-day" she has not communicated with since July 4th). She left so she does not need access to the condo mailbox. She does not know she can forward mail and I have not told her since this is an opp to communicate.