What you think is what you are

"There’s a traditional saying that the mind takes the shape it rests upon; the modern update is that the brain takes the shape the mind rests upon.  For instance, you regularly rest your mind upon worries, self criticism, and anger, then your brain will gradually take that shape – will develop neural structures and dynamics of anxiety, low sense of worth, and prickly reactivity to others.  On the other hand, if you regularly rest your mind upon, for example noticing you’re all right right now, seeing the good in yourself and letting go…then your brain will gradually take the shape of calm strength, self confidence, and inner peace."
Aqui