A poster on the Cat-Clicker mailing list ran into a snag. Her six-month-old kitten had lost interest in training. She had previously taught him to come when called, sit on a stool, give a "high five" with his paw, and to stand on his hind legs, and she had worked a bit on jumping through a hoop. But recently he had just seemed to lose interest.
List members made several suggestions. This, they reassured her, was not unusual. Her cat was neither lazy nor disinterested — he just needed to process the lessons. They recommended that she give him some time off. When she trains, they suggested that she make the task a little easier and build a stronger history of success before making it harder. They also recommended that she back off of old behaviors when she introduced a new one to give him a chance to focus on doing something new and different.
Another likely possibility was that her cat was entering adolescence. This is a time when the brain undergoes some changes that result in a temporary decrease in the ability to focus. Adolescent animals benefit from a drop back to the basics: short, simple lessons with high-value reinforcement. It's not a bad time to take a break from training for a few weeks, just to give him a chance to get through this phase of maturation and to keep the trainer from getting frustrated at the seeming lack of progress. When they start again, she'll likely find he's able to pick up where he left off and has a refreshed enthusiasm for training.