The storage of an event in the memory only involves the storage of a percentage of sensory data (what you touched, what you saw etc).
Upon recollection of the memory, the human mind attempts to ‘fill in the gaps’ to make it seem more complete. However, this process effectively changes the memory in a way that is dependent upon the state of the brain at the moment of recollection. Reconsolidation then occurs, which locks the memory into your brain again (again, only some of the sensory data is stored).
Because of this process, every time you recall a memory, it changes each time in a way that less accurately reflects the actual event.
The consequences of this are that not only are we unable to know the future, we are unable to know the past. Everything about us, including all our memories, is transient, and only exists in a single, brief moment.
The next moment that we experience will be a different person in the same body.
Isn’t that rather depressing? :’D