Access the custom fields of the product from a SKUInfo object within ShoppingCart

So we have custom fields and non custom fields on a product page. (and thousands of products, ok 250,000+ products) Information about a product, things like warehouse and just attribute type information. When I look at a item in the shopping cart, I cannot access any of those custom fields. I have tried the obvious ShoppingCart.CartItems[0].GetValue("Warehouse") returns null Tried ShoppingCart.CartItems[0].SKU.GetValue("Warehouse") returns nullWhen you go to the Pages tool then to the product page, then go to the form tab you can see all the SKU fields and my custom fields displayed.