Think Time is the time taken by a user to act/click on the next available link. Its basically the delay between 2 user actions. So, ideally this time delay should be added (only) at a single request/page in a single transaction. Why is that Neoload adds delay at multiple steps/pages. All the subsequent requests must be run/saved sequentially without any delay, the delay which neoload introduces makes it delay as various requests which does not really happen
You're right think time are set between 2 user actions. But the browser can also issue requests without user click so NeoLoad also adds think time for such pages especially when there's a delay for this requests to be automatically generated.