Managing state is one of the hardest things to do in any application. Angular 2 tackles this problem by making it easy to implement a reactive, uni-directional data flow that favor immutable operations. We are moving in the right direction in Angular 1 by moving our state and logic to models but invariably this raises a question. If we are moving to an immutable world, how do you manage mutable operations like forms in Angular? In this lesson, we are going to learn a surprisingly simple technique to isolate state mutations within a component using component lifecycle hooks.