Most of us wish we could improve certain things about ourselves. Lasting change is difficult: Many of our habits are deeply ingrained, and certain core personality attributes may be immutable. But even the oldest of habits and character traits can be altered to varying degrees, as it's never too late to change; with effort and determination, it is possible to be the person you want to be.
Quite simply, cognition refers to thinking. There are the obvious applications of conscious reasoning—doing taxes, playing chess, deconstructing Macbeth—but thought takes many subtler forms, such as interpreting sensory input, guiding physical actions, and empathizing with others.