Time travel stories are always difficult because of the mind-bending conundrums they create. If time is linear and there is no multiverse, then time travel has the high probability of really fucking things up. If there is a multiverse and you can travel to them, how do you even know which one to get to?
Or, perhaps, there's nothing but me, and everything is but a figment of my over-active imagination. Nothing else is real.
(My 12 year old actually asked me that last week; how do I know that anything else is real other than me? It's a deep question).
Oh man, that has GOT to be a hard conversation to have with your child haha because every answer you can give probably produces more questions XD
Haha. It was a lot of "How do you think this would work?" and he finally let me change the topic :)