here,

1. the second stage of life ie. the stage of the school-going boy is being referred to in the poem.
2. in the second line, simile has been employed.
3. the school-going boy is being compared to the snail.
4. No.The boy goes to school unwillingly.

We are the players on the world stage in the sense that we perform different roles here onthis world stage. We have seven different roles in our lives to play and at last, we exit from thisworld stage.

at the last stage of life, the man slowly loses his vision, hearing, smell, and taste and exits from the roles of his life like a child. therefore the last stage is also called second childhood.

The second stage of a human’s life is a schoolgoing boy. He slings his bag over his shoulder and is unwilling to go to school.

The first stage in a human's life is the stage of infanthood. Here in this stage,a child pukes in the nurse’s arms and cries to be in the comfort of his mother.

The poet compares the world to a stage because he considers all men and women like the actors and actresses in the drama who play role on the stage ie in the world.