Insanity is often defined as doing the same thing over and over again and expecting a different result. In some contexts, this might not seem to make sense. If you are learning something new in table tennis and can't get it right, you keep doing it over and over until you do get it right. However, the key point is this – if you are learning something new and keep missing, that means you are doing something wrong, and until you change that, you'll keep missing.
Change is the key when learning. And yet, over and over, players do the same old things and expect different results. I'll watch players lose because they keep blocking an opponent's loop off the end, and then, instead of doing some saturation training to fix their blocking, they'll go practice what they've always practiced – looping, hitting, whatever – and of course that's why they are strong on the things they practice a lot, and not strong on the things they don't practice as much. Or they'll be unable to return a certain serve, and yet, when it's over, rather than find someone who can do that serve so they can practice against it, they'll practice the same things they've always practiced. They won't even try to learn the serve that gave them trouble, when of course it might be a weapon they could use against others.
So go take a good, hard look at your game. What problems do you see? What can you change to fix that? Perhaps ask a coach or knowledgeable player the same question. Then address the problem.