Three or four o'clock in the morning is the most fatigued time of the day, especially when people stay up all night. At this time, people's spirit will inevitably be neglected. Even if I deliberately remind myself that we must keep clear-headed, but when we go forward for a while, we will unconsciously begin to want to doze off.

Especially last night, I didn't sleep well on the plane. It should have been the night before yesterday. Now it's three o'clock in the morning on the third day. I could not sleep at all when I turned the plane in the middle of the night the day before yesterday. I...