Broca's Area: Without it you wouldn't be able to say certain words easily and would stutter or be stuck on a word for sometime.
Wernicke's Area: Helps you make your sentences clearly which would make other's perceive your behavior as not being nervous because you can create sentences that are grammatically correct.
Pituitary Gland: Produces hormones and can make you have a adrenaline rush when in danger or make you really tried because you don't have enough adrenaline.
Hippocampus: Helps makes new memories to long term so it makes a huge part in who you are and how you behave.
Amygdala: It controls strong emotional responses like arousal and fear.
Thalamus: regulates how conscious and alert you are.
Basal Ganglia: controls cognition and voluntary movement. Lets you accurately move your body in ways you want it to.
Corpus Callosum: Without it your left and right hemispheres of the brain wouldn't be able to communicate making your ideas on both sides of your body conflicted sometimes.
Occipital Lobe: Lets you see tiny details in the world and enjoy the small things in life without having someone explain it to you.
Cerebellum: Controls fine movement coordination and balance. Impacts your behavior by making you not look sluggish or tired while you walk.