Did you know not performing as you think another player should in a group

[Destatiredux]

When you buy a job skip potion..."

This. Many times this. Jump potions are a means to be able to "jump" to where your friends are currently at in the story if you are a new player. It should not be an excuse to not know the workings of your job, and the game tells you as such. Even if you're jumping in by yourself, with no friends, the game provides many resources for discovering how your job works- this is why the novice network, the hall of the novice, training dummies scattered throughout the realm, and even palace of the dead (to some degree) exist.