So, as stated in the previous post, the character in this planned adventure game will have certain multi-purpose objects which they are always carrying. Many puzzles will rely on the player remembering that certain objects are used certain ways.
When trying to come up with a single iconic, multi-use item, I stumbled on the idea of...A SPOON. I had asked some people, and one suggestion that came up was 'screwdriver', it can be used to prise open things and screw or unscrew...er...screws, to poke things too. BUT I then realised, you can do any of these things with a spoon. Additionally a spoon can be used to scoop and carry things, eat things, dig, scrape, conduct an electrical current, make a sound when hit on things, as a catapult to fire small objects, as a mirror to see around corners and behind you or to signal people by reflecting light...
...Man...I need to start carrying a spoon around with me.
No other video game character I can think of carries a spoon, making it a nice, iconic object. Plus it's believable you could have a spoon in your bag, like suppose you like yogurts and sometimes buy one for lunch at the shop to eat at work? You'd carry a spoon around, right? Then in later installments, it just becomes a sort of running joke that the protagonist always carries Edward the spoon. Why Edward? Because Edward is the "spoony" bard from Final Fantasy 4. That means it even ties into a geeky oldskool gaming joke, further cementing it's place in this game!
Let's also assume the character has a pen and paper, so we can have a journal function, as well as other functions of paper and pen, and an empty plastic bottle, which is a multiuse item and also a Legend of Zelda reference, since in the Zelda series, the bottle is one of the rarest and most useful items in the game, functioning as a health or magic powerup, extra life, means of carrying quest items etc.
Finally a mobile phone. Firstly it's hard to imagine a twenty-something with no phone, secondly it doesn't kill dramatic irony since a phone doesn't always work, not everybody knows everything and phones don't always work, thirdly it facilitates amusing spoofs of Metal Gear games.
So, the inventory is: