Ask,
How many days are there in a person's life?
Do the math,
A person's life is only three days.
The past is yesterday,
It will arrive tomorrow,
Walking is today.
Don't forget yesterday,
Carefully plan tomorrow,
Seize today.
The author's intention in writing this poem is: don't forget yesterday, plan tomorrow carefully and grasp today. I hope you are still by my side like a song, and I will still stay in your heart to express a good wish.
or
Yesterday has become the past. It takes decades to remember. However, for myself, it is important to live today well. Think about what you still want to do and what you should do, and you can only do it quickly. There are other places to go and go, and you can also actively look at them. "The sun is still shining, and the old age will be later and more orange." For tomorrow, it is difficult to calculate how many miles there are.