To whom does the ancient Mariner tell his story? Why does he chooses this person? Support your response with textual evedence.

A wedding guest (one of three) He grabs him by the wrist and puts his hand on his chest and he can't walk away when he looks in his eyes

The poem starts where Mariner stops one of the three wedding guests passing starts talking to one of them, who was reluctant to listen.

Explanation:

Though the guest does not want to listen to what the Mariner is talking about, those 'glittering eyes' held him and the mariner's spell was powerful to him. The guest was forced to listen to him like a small child, forgetting about the wedding that he came to attend.

Reference from the text:

'There was a ship,' quoth he.

'Hold off! unhand me, grey-beard loon!'

Eftsoons his hand dropt he.

He holds him with his glittering eye-

The Wedding-Guest stood still,

And listens like a three years' child

Coleridge chooses a 'wedding' as a symbol in this poem. Along with other prominent symbols in the poem, this is the first and the most important one. His idea to determine the underlying idea of 'new beginnings, happy occasions, to rise up' is an essential part of the entire poem.

This poem showcases to readers the importance of the principle of life, its religious effect on our community, selflessness and forgiveness. A sense of purity and freedom can be observed when we read the last part of the poem and it says, the ship began to move. Here, we can understand that the regeneration of Mariner has begun.

Reference from the text:

Is gone: and now the Wedding-Guest

Turned from the bridegroom's door.

He went like one that hath been stunned,

And is of sense forlorn:

A sadder and a wiser man,

He rose the morrow morn.

Without the symbol of wedding (a new beginning), we couldn't have understood that the wedding guest who was reluctant to listen in the beginning has now changed/transformed into a a person who looks forward to live a better life.