It's one thing, holding open the door for someone at a grocery store, or the library, or just about anyplace else. But the doughnut shop is a different thing altogether. This is a get-in-and-out-as-fast-as-you-can operation. There's no room for courtesy or chivalry here.
A memorandum is written not to inform the reader but to protect the writer.
I'm a four star general in this thing, and you don't rise to the ranks of a four star general by hanging about the house being the perfect dad.