Spell Mastery

You have mastered a small handful of spells, and can prepare these spells without referencing your spellbooks at all.

Prerequisite: 1st-level wizard.

Benefit: Each time you take this feat, choose a n­umber of spells that you a­lready know equal to your Intelligence modifier. From that point on, you can prepare these spells without referring to a spellbook.

Normal: Without this feat, you must use a spellbook to prepare all your spells, except read magic.

Source: Pathfinder Core Rulebook