After reading my explanation as for why their was a nut by the campfire, I am sure that many of you scratched your heads and said something along the lines to "well, it sort of makes sense but it seems to be rather coincidental." You would be correct. Coincidence does have it's place in life and does happen, but the real reason that the nut only appeared after you meet with Charles is the more pressing design issue of enforcing the stories linearity.
One of the issues that comes up when creating an adventure game is how to deal with the player get ahead of the story. Many adventure games simply let the player do things ahead of the point in the story where they make sense. For instance, I could have had the nut located at the camp site through the entire game. The player would have then been able to get the oranges before they were able to. Stuck players wouldn't know why they were getting the oranges but figured since they could they might as well. The whole sequence with Charles would then have had it's impact removed. Some people undoubtedly will have the opinion that it wasn't a humorous sequence anyway, even if the designer does see humor in the situation.
By not having the nut appear until the time in the story when it is necessary may be considered cheating, but it doesn't really impact the player's enjoyment of the game and the players who have a similar sense of humor to that of the designer will probably appreciate the game more as a result of this decision. Of course, in my case the decision was strictly a story enhancing decision. Other times things like this are done to prevent the player from getting ahead of the game. Locked door puzzles are quite common in story based games.
I am sure there are a lot of gamers out there who are saying that linear stories are not appropriate for games. Some people feel that games should have open universes that allow players to do whatever they want. There are many games that do have such freedoms but these games have their own issues. One of the biggest issues with open ended worlds and the freedom to go anywhere at any time is that those types of games can't easily be broken down into small chunks and slowly released to the player as the game is developed. Small episodes is a big factor in my decision to actually start this project. If I had to create the entire game world and release the game as a single large game it is doubtful I would have started this project. I am not saying that I wouldn't do that type of game, just that at the time such a game didn't work into my plans so if I would have planned One of those Weeks to be an open ended free-form game then it probably would not have left the drawing board.
While I do enjoy games that give me total freedom over where I go, I also like linear games. Both have their advantages and disadvantages. Some people like pie, others like cake. I like them both and am glad I live in a world where I can choose.