Question

why is it not possible to record all events that have occurred in the past

Answer 1

it is because of lack of technology at that time by which we cannot collect records of all events that had been occured in past.

Answer 2

It is not possible to record all events that occurred in the past because, ther may not be available facilities to record.
Situation may not be convenient.
More over in past there are no cameras or other facilities.
After the Britishers rule, that people burner more evidences of our country.
Some records may vanished due to natural calamities etc.
Some times there will be no proper proofs to record the event.
Eg: People say that loard Rama is a king and god
But we did not read about the evidence of king in text books. Because there is no proper proofs for it.
I hope it may help u
tq