I think at least the notes make sense. He is writing in 2020 so of course it would appear in 2021.
If you know Schrödinger's cat, then you would understand that even if he wrote them in 2020, it has not happened yet. It can only appear the moment he wrote it and put it on the wall.
Perhaps you would also be confused about the USB existing in 2021 but apparently it was lost (JG dropped it) in 2020. That is called Bootstrap Paradox.
Apparently, they are in the 4th dimension and time can exist at the same time even in different planes. Some things might be happening in the past that can only occur once they have been "done". People continue to change the past, and can affect the future in real time. Objects can exist depending on the "world" they occur. This can be explained by Many-Worlds Interpretation of Quantum Mechanics.
Perhaps you would also be confused about the USB existing in 2021 but apparently it was lost (JG dropped it) in 2020. That is called Bootstrap Paradox.
Apparently, they are in the 4th dimension and time can exist at the same time even in different planes. Some things might be happening in the past that can only occur once they have been "done". People continue to change the past, and can affect the future in real time. Objects can exist depending on the "world" they occur. This can be explained by Many-Worlds Interpretation of Quantum Mechanics.