[@Pripovednik]That's how druids and a few other casting classes work; they have a pre-determined list from which they can choose to cast spells from. However, they  have to prepare them ahead of time through prayer/meditation for an hour during the day; and only so many as allowed by the spells per day chart. At level one, I'd only be able to prep three 0-levels and two 1-levels per day. The spells on my sheet are all 0 and 1-level spells that I can chose to prepare.

In a sense, druids, clerics and wizards have unlimited spells from their rosters 'known,' whereas sorcerers and bards have to pick which ones they actually know, but are able to cast those at will without earlier preparation. Sorcerers and bards can cast anything they know spontaneously, but these other classes are limited to the spells they have prepared for the day and need to cycle out spells next time if they want to be able to cast others.