You want frustration?
Try completing one with two cats in the house. He would have been picking pieces up off the floor after the cats got through playing polo with them each day. Cats just love small things like that to slide across the floor.
Right now I'm just trying to read a book without a cat climbing up on it. 😁
That was one helluva project to keep his brain interested in functioning. Good for him! And good for the puzzle people to come up with that last piece.