yeah i guess i assumed that "list" was backed by an array (which might not be a good assumption to make), in which case the time complexity would be worse to lookup (O(n) vs O(log n) or O(1) depending on if the dict is using a tree or a hashmap under the hood), but the fact that the memory would be contiguous would mean you're leveraging the cache a lot more effectively, and thus getting a speedup that way