If the term “double-double, animal style” is Greek to you, then you’ve likely never stood before a white-uniformed young person in a peaked cap, specifying what sort of onions you want atop your In-N-Out burger.

Plenty of regional chains enjoy a strong local following. In the instance of 75-year-old In-N-Out, we’re clearly talking about a cult—one that makes a hardcore Chick-fil-A fan seem wishy-washy. What is it about an old-line burger chain that inspires such loyalty?

The food is definitely a hook. But part of the appeal is the insider-y feel that comes with knowing the brand’s rich array of peculiarities. What other operation has a thing about palm trees? Or quotes scriptures on its fry sleeves?

Fortunately for you newbies, this week’s edition of our Restaurant Rewind podcast serves as a primer on the peculiarities that have endured the concept to generation after generation of West Coasters. It’s delivered here in anticipation of the chain’s expansion to the East Coast.