Is it possible to have my rMBP's lid closed and only use the Thunderbolt display? Every time I connect the thunderbolt display to the rMBP while the lid is closed, it will wake up the computer from sleep mode briefly and then go back to sleep. I have to keep the lid open for the TBD to be on, and if I close the lid it goes to sleep. I would really like to use by TBD with the lid closed. Am I doing something wrong here?