Well, they are not supposed to, yet... One of the most notorious among gamers when I was a teenager (okaaaaay maybe not strictly a 'text' adventure game) was Delphine Software's infamous 'Operation Stealth' where if you forgot to pick up an item say, at the beginning, you could not finish the game and you could not go back. You had to do precisely what the author describes at the beginning: call saved games or start over.