He didn't say "without copy and paste".

Just copying the expected value from the test into the body of the implementation will make the test go green, but it's completely un-DRY, so you'd have to rip it out and replace it with a non-c&p implementation during the necessary refactor phase anyways.

Wikipedia agrees with me on this, and they cite to "Test-Driven Development by Example" by Kent Beck, the original TDD guy.

So, TDD as I learned it discourages c&p from the test. However, Morendil, now you've got me interested in talking about the possible benefits of a c&p-permitted approach: for example, I can see how it might force the programmer to write more sophisticated tests. Though on the other hand, it might also force them to spend a lot more time on the tests but for only minor additional benefit.