Counted by average age of 75, lifetime of a human being is merely 900 months. Draw a 30*30 table on a piece of A4 paper and tick one box every a month, you can see your life passed on this paper.

人生其實只有900個月，而你可以用一張A4紙畫一個30x30的表格，每過一個月你可以在小格子里打勾，你的全部人生就會在這一張白紙上。