If I copied your brain right now, but left you alive, and tortured the copy, you would not feel any pain (I assume). I could even torture it secretly and you would be none the wiser.

Well.. Let's say I make a copy of you at time t. I can also make them forget which one is which. Then, at time t + 1, I will tickle the copy a lot. After that, I go back in time to t - 1, tell you of my intentions and ask you if you expect to get tickled. What do you reply?

Does it make any sense to you to say that you expect to experience both being and not being tickled?