Hi Chris. Would be great to see more of your caching / performance videos as there seems like there isn't enough information out there and its a massive part of a web site. For example, what happens if you have a comments list and you need to find out if the current_user has already commented so don't show the "add comment" button. You won't have the users ID if the comment is on another page, so how would you get the users ID? Would you do an API call to the server via ajax, this seems like it could get sluggish OR maybe not?