Paper Mario FAQ

Q: Why are you doing so much of the game out of order?
A: Paper Mario is very trigger based as far as the game's sequencing. Completing a chapter essentially tells the game that everything you would casually need to do up until that point is done since in theory you should have had to do those things. The only things this does not apply to is your inventory (items and badges), your current roster of partners, as well as your current hammer/boot upgrades.

Q: Why are you fighting the Fuzzies in Chapter 4/getting the Super Hammer in Chapter 2/etc?
A: Due to the triggers the last question mentioned, certain things need to be done in order to put the game state back in certain chapters so that we can actually fight the boss of that chapter and collect the Star Spirit card for that chapter.

Q: What are you doing jumping in and out of loading zones?
A: This is referred to as LZS (short for Loading Zone Storage) and involves jumping into a loading zone and then executing continuous frame perfect jumps out of it. What this does is overlap any other loading trigger you hit while jumping to be overwritten by the stored loading zone. With the major example of LZS jumps done into Star Spirit cards, this allows you to collect the card without having to do the Peach intermissions associated with them and avoiding the game changing the amount of Star Spirit powers you have. Other uses of LZS includes skipping the first Jr. Troopa fight as well as getting Bow among other things.