Exactly why, even if you solve the going back in time problem, time travel doesn’t work.
You also need a “going back in space” solution to orient you in 3 dimensions relative to the position of everything else in the universe at the time of your time/space reinsertion, and surely that’s a more difficult problem than just the reversal of time. Without the spatial correction, any time travel would put you in deep space or inside a rock with a probability of survival so near zero as to be zero.

Primer solves this nicely. The problem is, by the time you've watched and understood Primer your brain has been so messed up that you're a different person, thus resolving the paradox of the lack of paradox.

Interesting. Never heard of it before.
I must watch this “mouth of madness” type movie.
I wonder who I’ll be afterwards.