I've been operating under the assumption that shepherd's pie is lamb, and cottage pie is beef.
I threw a pork shoulder into the slow cooker as I ran out the door this morning, so it's pulled pork for us tonight.
The shepherd's pie=lamb / cottage pie=beef was my understanding, too.
I love putting ingredients into the slow cooker and walking away, only to come back hours later to tasty noms that I almost forgot about. It's like giving myself a Christmas present.

Edited to add: My short term memory is somewhat comical with its scarcity. I think it's an attention span issue, really, but it comes across as a memory issue. But, still, you'd think I'd remember putting a big hunk of meat into a slow cooker and adding seasoning and liquid to it. I mean, really! That takes
some effort.