20. You Can Blame The Amygdala For Never Forgetting Stuff You Want To Forget
All those terrifying, embarrassing, and heartbreaking things from your past that you just can't shake from your memory exist because of the amygdala. When these things happen, the amygdala releases adrenaline and cortisol which enhances memory. Basically, those memories you want to shake are imprinted on your brain thanks to those two hormones.