Sadly, the 4D massage chair doesn't massage your past.
A good massage is going to exist in three dimensions. A 2D massage would be some pressure on your skin or something. To really get in there you GOTTA work the third dimension! But think of how great a 4D massage would be! You'd start feeling really relaxed and then think "Oh, that's right, I have to schedule my massage for tomorrow." You'd get there already happy and the tension would be dripping away. And then you'd start, and that happy feeling would stretch both forward and backwards in time. The tension of causality would be gone! But until we're there, this massage chair is the next best thing.