4 reasons you might change the subject with your horse or move on too quickly.
Fear: The task makes you nervous, or it makes your horse nervous. You're not sure if you can safely navigate the hazards and you feel it's simply smarter to move onto something else. But this tactic inadvertently teaches two horrible outcomes. Your horse becomes aware that you back off and make life easy when he or she acts up. Next time it will be even harder to approach this subject. The other is you. You become uncertain about your own capabilities and you become what we call an "avoid-aholic." The only thing you must not do when you feel fear, is change the subject. Don't do something unrelated to what's causing the fear. Instead break things down to smaller chunks and be willing to take longer training sessions to get past the problems.
Frustration: The task seems too big and too hard. Nothing is going as imagined, therefore... move on. Except that's exactly why you shouldn't move on. Have you ever heard the phrase, "end on a good note?" Well... what does "a good note" mean to you? To me, a good note is an "A" or "B" score. Not a "D" or "F." If a goal is too big then cut the goal in half and find a way to get a great score on a simple aspect of that overwhelming subject, but don't change the subject until you've made noticeable progress.
Bored: You feel your horse is the kind of horse that gets bored easily so you don't like to spend any length of time improving one single subject. Instead you like to dance around from game to game and your horse never really gets better at anything. From experience, you know that if you get your horse to give you what you want once, you shouldn't ask again because that will bore him and make him resent you. The problem is, you've taught him to be a "one and done horse." You've avoided repetition because it bores him or it bores you. Either way, you've created a situation where you can't do things three times, or even twice, and now you have to make special plans for every activity to make sure your horse is always entertained and never bored. But what you're missing is a simple truth that boredom is like fear and frustration. It's a negative emotion that shouldn't be skirted. It should be addressed. When you're horse is bored, don't entertain him every time by changing subjects. Instead, teach him how to deal with his boredom and be okay with repetition and rewards within the same subject matter.
Confused: Your horse is not doing what you want and you're not sure you're asking right. So instead of persisting with your best guess, you decide to change topics and move onto something you do know. It seems logical but, ironically, it's the most counterproductive measure you can make. Let's take lunging or circle games as an example. Let's say you want your horse to canter, but you feel you're asking wrong and getting nowhere. So you quit and change subjects, but what you should really do is break the goal in half even tenths, if you must, and keep using those same lesser tools and techniques. You might not get your canter but what you do get is a "yes" answer from your horse when you ask. If you break cantering on a circle down to a tenth goal, all you really need is for your horse to speed up when you ask. If he says yes, that's fantastic. That's something you can work with tomorrow after you do some research about tools and techniques. But if he says no, and he won't even take a faster step when you ask, then you give up and change subjects... that's called "ending on a bad note." It's not about the canter, it's about the question and answer process. If you make the question smaller but keep it related before you move on, you can start to get some yes answers and end on a positive note for that day.
Don't like drilling: This is a bit more about you than your horse. You find it hard to focus. It's true that you might think it's hard on the horse to repetitively practice the same game until you ace the tests, but what' really going on under the surface is you don't like tests. You like variety. If this is true, you may never experience the variety that progressive precision offers. You may never experience tempi-flying lead changes, spins, piaffe, slide stops, and more because you struggle to value repetition. However, if you just double up on the rewards, repetition can be super fun and very enlightening for both you and your horse. Whatever you do, do it a little bit longer. Do it daily, and mark your progress. You'll be amazed at what's possible in ten sessions or more on the exact same subject.
Socrates said "There is no learning without remembering." citation. To remember you must practice, then test to see if your practice is done. The best test in the world is to see if you get an "A" score on any subject matter. We use that model in school. Let's use it in horsemanship. If you aced a test in high school, even if it happened decades ago, you will more than likely ace that same test today after a short warm-up. This is why schoolmaster horses are so valuable. They don't require a master to perfectly navigate every weight and balance with leg cues and rein cues. You simply ask and they respond happily. They know there job because a great trainer helped them remember their job, in part by never changing subjects on a bad note. It's fine to have multiple subjects on which to learn and grow, but the timing of changing subjects has as much to do with learning as the subject itself.
Here's my challenge to you: When you feel bored or feel your horse is bored, when you feel afraid for you or your horse when you feel frustrated or your horse feels frustrated, when you feel confused or your horse feels confused, hang in there a bit longer and get a passing score on a simple test related to that same subject... then move on. But be sure to come back to subject again on the same day and the day after that until you start getting "B" and "A" scores regularly. Only then will you grasp Socrates' formula for learning and become a master in the subject of your choosing.