Danielus interruptus

There's an ongoing battle at our house. As soon as Chris gets home, he wants to share with me the details of his day and I inevitably have a bunch of stuff to tell him. But Daniel hears the truck pull up and it's "Daddy's home!" - and out the door he goes. An hour later, he could still be chattering away at Chris.
So we're trying to teach him that when mom and dad are having a conversation, he needs to wait until we stop for him to speak. But I'm learning that it's a common issue for parents of small children, and Parent Center explains why:
First, kids don't have a developed short-term memory yet. So if I make Daniel wait five minutes, he's likely to forget what it was he wanted to tell me. Second, from birth we kind of train kids that our world revolves around them. As they gain independence, we as parents have to do some retraining.
But then there's the concept of emergencies. Is it okay to interrupt if he's spilled something? If the dog has the cat by the tail? If he needs a kleenex? It's complicated - especially when you're four.
--Misty