Have you done the 4-phase drill (or something like it) to teach the concept in the yard?
Have a line to a blind of 100 yards or so, and put a bird boy at 20 yards about 10 steps off the line. Start out throwing away from the line, picking it up, and then running to the blind - i.e., go here, don't go back over there. You can vary this if you need to, as I had to start out with birds on the blind and bumpers on the throws or we were going to have a heckuva fight. If the dog tries to go back to the mark, stop him and cast him to the blind. I would use lots of attrition here unless the dog really flipped me off. This is a clear illustration of "go here, not back to that old fall."
Once he has it at 20 yards, repeat at 40 yards, until you get out to 80, which is of course the most tempting. Then you will come back to 20 yards, only this time put the bird boy where the throws were landing and land the throws where the bird boy was previously - throwing toward the line but not on it. Even more tempting for the dog. Again, handle away from the fall and only use pressure if the dog clearly goes independent on you. Keep moving out as you did before. Another clear lesson in "go here, not back to that very enticing old fall."
If you want to finish, come back to 20 and land the marks on the line for pushing through old falls, repeat the same procedure except I would not stop the dog if he breaks down at the old fall. Remember, what you want is for him to realize there is no bird there and keep going and not blow up on the last bird of a JH title . . . but I digress. If I had it to do over I would send the dog on this one, putting my hand up in a back cast as soon as he left the line. When I saw his tail drop, indicating he was breaking down, I would give him a loud "back" and keep doing it until he took off for the blind.
You can to this same thing with under the arc throws as well, and you will have taught the dog the 4 basic concepts. Be sure to do it throwing from both sides as well; remember that dogs are not good at generalizing. And of course you realize that this is not much more than a one-legged pattern blind with diversions.
This uses a blind instead of a memory mark, but the concept is the same, and you might be able to teach it better by removing the stress of having to remember where the memory bird is. When you cue the dog for "dead bird" or whatever you use, it should be clear that the dog is to keep moving until further directed by you or until it comes across a retrieve object. The dog would also expect to be handled, and you can teach what you need to teach without a lot of handling on marks, which you want to avoid as much as possible, all other things being equal.