Tell me what humans are afraid of.

When I was in the fourth grade, I found that if one day your eyes suddenly disappear, your brain will automatically supplement the images that the retina can't capture, so in a short time, you won't realize the fact that you are blind at all. During that time, my sister just had an operation and her thyroid was removed. Her body will gradually stop secreting thyroid hormones and must rely on artificial hormones to maintain her life, but she is still recovering, so she has not started taking hormones for the time being. As a result, the thyroid hormone in her body gradually became much lower than that of ordinary people. (Note: Thyroid gland is still a relatively common disease, which is not dangerous, so don't worry. ) Thyroid hormone is one of the key hormones in the human body, and the common hyperthyroidism in our life is caused by excessive secretion of thyroid hormone. If there is too little thyroid hormone, it will produce the opposite situation to hyperthyroidism. The basic metabolism of the body will be reduced, and the common short-term manifestations are: if you can't eat, you will get fat, and your understanding and intelligence will decline. Another side effect is temporary blindness. I didn't know at the time.