If you are anything like me then, the whole time line issue/scenario from the Terminator franchise probably baffled you. I'm assuming that there are multiple time lines since that is seemingly the only way to explain things in this universe. How else could John Connor send the man who would be his father back though time. Someone at io9 was crazy enough to sort through all of this. If you view the end of each line as the beginning of the next one, i.e. the ending of a is the beginning of b, it starts to make sense.