First time jump

The first time jump the movie showed us was the “actual” first time jump. The first time jump was when David saw himself in the mirror when he was watching the footage from his 7th birthday. I think that timeline played out just like we saw in the movie but I think that in that timeline David also tried to save his dad and failed. At the end he realizes that he can’t change the past because the effect won’t always end up the way you want it to.