Practically all modern self-searching starts with "Cogito, ergo sum", i.e. "I think, therefore I am."
I think, I perceive, and I see the world with utmost subjectivity. I find myself, quite naturally, in the centre of my world. My historicity defines the history of my world. This I became so valuable I cannot imagine a world without it. Indeed, I MUST be, be it in the afterlife, an endless cycle of rebirth, or simply as a tiny flux of consciousness stored in some corner of the universe.
Or, I think, therefore like every thinking things I exist. I share an objective world and history with many other things. This I is as much significant as others of its kind. Like them, it can arise from and dissolve into unconsciousness. This doesn't allow an eternal soul but can bestow one with a full moon over a pine forest with an 'ah!' barely audible, a sunrise that set our whole life ablaze, in short, the pathos of things.