What suddenly occurred to me when I saw my father's gray hair?

Speaking of which, I think most of it is my father's hard work. Seeing his white hair reminds me of his hard work for so many years. I have to say, what I think most is the scene of my old father sweating under his eyes. It's not the change of time, but the passage of time. My father is getting old bit by bit. From the prime of life to the old age, as a son, it is still quite uncomfortable to see my heart.