bedtime drama

We have been struggling the last while to get Zachary to stay in his bed at bedtime.  He initially goes down easy enough, but after a couple of minutes will reappear with some demand for more milk, more books, or a why don't you tell me bout it mommy?
The first round of demands can be kind of endearing, but by round five we are done.
Here is an exchange that happened the other night:

Clint: Zach, if you get out of your bed one more time we are going to have to shut the door.
Zach: Nooo! I no want you to shut my door daddy!
Clint: Then STAY in your bed and go to SLEEP.
Zach: Geeez this is a disaster---why this always happen??!!!!

Zachary, we ask ourselves the same question every night.