Shi Tiesheng takes notes. If you stand, it means that you are in control of the present. Writer Shi Tiesheng wrote in the novel "Retirement Notes" that if you look forward to the future from the standpoint of childhood, you will say that the future is uncertain and you will say that the future is boundless; But if you stand at the end and look at the trajectory of your life, you can only see one road, and you can only see one destined road. Therefore, fate has different interpretations from different angles, and the most important thing is to master the present. Therefore, Shi Tiesheng's closed-door notes mean to master the present while standing.