Ideas(Sorry if they don't help or aren't what you are looking for):
- A mysterious train station in the middle of nowhere that the main character somehow ends up there. The main character can go on the train or can stay at the train station. The main character wants to find a way out of the train station. A flashback can be about the main character before ending up at the train station.
-The main character can be visiting an old friend that they haven't seen in a while and aren't really good friends with anymore. The main character can get flashbacks of the time main character spent with that friend. The main character can want to rebuild the friendship with the friend.
-The main character goes on a boat trip with friends and/or family. They used to go to the beach as kids and the main character can get flashbacks of that before going onto the boat. When they get on the boat they get stranded in the middle of the ocean.
-The main character is in space and locked in one of the rooms on the spaceship. After hours of being stuck in there and helpless calls, the main character gets flashbacks of being back on Earth.
