Is this real? Or has this been happening inside my head?
It has been two years since the Battle of Hogwarts and the end of the Second Wizarding War. After the war, Harry Potter became an Auror and has helped to reform and revolutionize the Ministry of Magic. Trials are still underway for those that sided with Voldemort, while others try to pick up the pieces and rebuild their lives, though not without some consequence.
This era, more than any other, will deal with timeline changes in present-time as they occur. Memories will remain fully intact up until those changes begin, and the more that is altered, the more fractured those memories will become.