"Rift"

  Your grandmother got pregnant out of wedlock, and the natural father left after finding out.

  Fortunately, your grandmother met a young man, of the same age as she, who married her and took care of her, so the child would not be born out of wedlock.

  However, your grandmother died while giving birth, leaving your step-grandfather to care for the child.

  Your step-grandfather soon met and married a woman of the same age as himself, and they gave birth to a child (your step-uncle) of their own, who was three years younger than your father.

  Your father lived with his stepfather until age twenty, where by that time, he had married, and you had been born.

  At age nineteen, your step-uncle mysteriously disappeared.

  At age nineteen, you are pulled into a time rift and are sent back in time, where you quickly adjusted and met a pregnant woman, whom you married and cared for until she died giving birth.

  You privately searched for the man who impregnated her and found that he looked exactly like your step-uncle, in the most recent photographs that you had seen of him, before he mysteriously disappeared.

  Realizing the situation, you thought it best to not reveal what you had done or what you had found out.

  Not long before you were pulled into the rift, your step-grandmother had told you that you were the spitting image of your step-grandfather when he was your age.

  You then realize why you and he were so close.