Why, when given a blank slate, would you decide that your backstory is just some random average joe?

Here is the backstory for my sorcerer (sailor) - Pavel was a ship’s windcaller, abducted by a notorious pirate because he was the child of a dragon. The pirate raised the half-elf, half-dragon, as they sailed across the oceans of Faerun, becoming bloody conquistadors. But as he grew older, Pavel rejected the violence of his upbringing. He killed the pirate captain who raised him, along with much of the crew. Having made a daring, narrow escape after setting the ship on fire, Pavel barely made it to Baldur’s Gate alive. After arriving, he decided to lay low and recover from his injuries, when all of the sudden- tadpole.

Will any of this be referenced in the game? Aside that he is a sailor, of course not, but that’s okay. I don’t need the game to tell me I’m a super badass. Give me a blank slate and I’ll fill in the blanks myself. As far as I’m concerned, that’s the point of a role playing game, and unless I’m playing a truly stupendously great character (The Nameless One level at least) I prefer to come up with my own character in my head.