I first played All Things Devours 5 years ago as one of my first pieces of interactive fiction, and was very confused and felt it was impossible.
All Things Devours is a time travel game, where you must work together with past or future selfs to navigate several puzzles, subject to certain restrictions.
This game can be solved much more easily if you keep a detailed list of where you are and what you are doing at each turn. That way, you'll know where (or when) to be with other incarnations of yourself.
Fortunately, it's not necessary to jump around too much. A similar game called Fifteen minutes involves 8 or more copies of yourself in the same room, and it gets very tedious by that point.
All Things Devours is a classic.