Let me give you an example. If you lose 15 points, then after participating once, you will need to earn an extra point every day to make up for it. If you participate a second time and lose another 15 points, it means you will need to earn two extra points every day to recover. Even if you try to double your efforts (which doubles the cost), you can only accumulate points day by day. Meanwhile, there are many people who didn't participate, and they are continuously surpassing you. Moreover, the point cycle is 15 days, so participating a third time will be very difficult, or the cost may not allow it, meaning you can only wait for the next 15 days. In other words, this is the situation when losing 15 points.