Psychological knowledge is like nuclear energy. You can use it to generate positive energy or use it to destroy some one. Most people learn psychology for the understanding of mind and human behavior. Few user it to comfort others like understanding their problems or solving their problems.
Few people use this dangerous knowledge to destroy and manipulate others. It’s like knife. It can cook as well as kill. Depends entirely on the person possessing it and how he intends to use it.
In any case, I strongly recommend psychological books to understand the working of insane and predictable human mind. You will laugh after learning about fallability of our mind and it’s decision making ability.
What’s something that you tried to understand but couldn’t?
Mind is irrational.