The Condition called Hyperthymesia combined with Physics
It is possible to 'time travel' if you have Highly Superior Autobiographical Memory (HSAM)
Those with HSAM have a condition called Hyperthymesia and they are called hyperthymesiac.
They are able to describe days in the past, in great detail. They do this by indexing their brain on dates.
My theory is simple.
There is a way to re-index your brain, not use dates but rather sound(songs/music), taste, meditation, etc. All that happens is, you re-index how your 'memory' is stored. Instead of days, you use music.
My theory is you can use this to talk in time in a MWI environment, by accessing memories via songs you can Mandela Effect memories from other 'Tangent Timelines'
Furthermore, I believe people who would be able to do things if they were able to do this...
Hypothetically, if you were able to do this you would then be able to tell people about Trump winning and the US collapsing back in 2022.
I don't know if this is time travel, as much as knowing where you are going.
This is my theory, it is based on MWI theory, hyperthymesia, and Hawking's last work about localized universes.
My really crazy theory is that there is a timing based off The Fluctuation (The Delta) of the true speed of light that is bound by the "Reflected" Speed of light.
Like a sine wave over the ZeroLine
It is how you can echo and setup warnings ahead.
I mean Trump still wins, but here you are. As predicted
My prime theory is Free Will at its core is a myth