In the third installment of the franchise, Pirates Of The Caribbean: At World's End , Jack is seen talking to Lord Cutler Beckett and bargaining for his freedom.
But the original scene not only shows how Jack was indebted to the crown but also how he got branded with a P on his wrist. (Read the text on the image)
Had he been selfish at that time, he would've had a really comfortable life. But he chose to do the right thing. His past speaks much more about him than we thought.
Here is the original video of Captain Jack Sparrow and Cutler Beckett (Lord Beckett... but no one really cares):
This scene was modified (quite a lot) and did not really talk about Jack's past. But now, we know why he was branded as a pirate and eventually became Captain Jack Sparrow. And here we were, thinking we had him figured out... well, almost!