The list author says: "this list is just a collection of the items i think most photographers need, the things i want, and some things i have. everything above the bag is what i do carry on an everyday basis. (i do not own the 105mm lens, but if i did, i would make sure i carry it with me)."
"pay attention to the filter size you will need. i chose to show this fish eye instead of the 1000 options because i think the main purpose of a fish eye is for fun shots. quite honestly, for the price, the effect achieved and the image quality using this is pretty good."
"i only put it on because i want to try and ultra wide like this. it seems like it may be useful, but if you have a decent standard lens that gets you down to at least 18mm, it is not entirely necessary."