When tomorrow turns in today, yesterday, and someday that no more important in your memory, we suddenly realize that we are pushed forward by time. This is not a train in still in which you may feel forward when another train goes by. It is the truth that we've all grown up. And we become different.
(When tomorrow turns into today and yesterday, and finally becomes a day that is no longer important in memory, we suddenly find that we have been pushed forward by time without knowing it. This is not the illusion that we are moving forward when intersecting with adjacent trains in a stationary train, but that we are actually growing and becoming another ourselves in this matter.)