Plagueis and Palpatine's quest for immortality involved using the Force to control time. They discovered time travel was possible by accessing the world between worlds. Palpatine manages to do it, and while traveling 75 years into the future, he senses a being more powerful in the Force than anyone he's ever encountered: Rey. So in TROS, Palpatine appears out of the Force-Time vortex and takes Rey back 75 years into the past... to about 10 years before the events of TPM. Rey manages to escape from Palpatine, but knowing Palpatine would surely find her, she cuts herself off from the Force like she saw Luke do on Ahch-To. She takes Luke's last name, and in a twist of irony, she ends up a slave on a desert planet, just how she started out. She accepts that she's stuck there, and the last shot of the saga reveals a pregnant Rey/Shmi looking out at a twin sunset. So all the speculation about Palpatine using the Force to create Anakin is true from a certain point of view. He used the Force to bring Anakin's mother from the future. Who is the father? I don't know, maybe Ben/Kylo? That's for the audience to decide.