Mongoid Object.all seems to return a lot of []

Question

Why doesn't this work:

ruby-1.8.7-p249 > List.create :search_terms => 'foo'
 => #<List _id: 4c9044a02249c7a5e2000001, search_terms: "foo", user_id: nil> 

ruby-1.8.7-p249 > List.all
 => #<Mongoid::Criteria:0x1030dea90 @klass=List, @documents=[], @selector={}, @options={}> 

ruby-1.8.7-p249 > List.all.documents
 => []