A person could say it when they are filling out a form or in an official situation where their race is being questioned in a way that makes them feel uncomfortable. By stating 'I'm black end of story', they are quickly and firmly answering the question without allowing any room for further probing or potential discrimination based on their race.
Someone might say it when they are facing discrimination. For example, if they are being treated unfairly in a job interview because of their race, they could use this statement to assert their identity and make it clear that they won't tolerate any form of racial bias.
A student who fails an exam might say this. They know that they can study harder, learn from their mistakes, and improve in the future.
A survivor of a shipwreck could say it. After being lost at sea for days, facing hunger, thirst, and the fear of never being found, when they are rescued, they might say 'now i'm alive to tell the story' because they lived through such a harrowing experience.
Someone might say it when they have completed telling a story about an event in their life, like a funny incident at school or a challenging experience at work.
Someone might say it when they want to cut off a conversation about a past event or relationship. For example, if they don't want to dwell on it anymore.
A person who survived a major earthquake could say it. They were in a collapsing building, felt the ground shaking violently, but managed to escape. Then they can say 'I've lived to tell the story' to express their relief and to share their harrowing experience.
Someone might say it to show that they've overcome a great ordeal. For instance, if they were in a car crash and managed to survive, they'd say this to convey that they are lucky to be alive and can now share what it was like during the crash.
In a situation where a person is sharing their life experiences at a gathering. If they start with the time they first got to know you, they could use this phrase. For example, if you were their first real friend in a new city and they are now reminiscing about their journey there, they might say 'calling you my first story' to emphasize your importance at the start of that new chapter of their life.
Let's say you are telling a story about a school project. You start with how the project was assigned, the difficulties you faced during the process, the solutions you came up with, and finally how you presented it. After covering all these aspects, you can say 'and thats tge end of the story'. It marks the end of the account, showing that you have completed the story - from the initial situation to the final outcome.
Someone would say 'that's my story' when they want to end their account of an event or experience. For example, after telling a friend about how they got their first job, they might say it to emphasize that it was their unique experience.