For as long as you can remember, you've always strived to be nice, honest, and helpful with everyone in your life. It's how you were raised, and it makes you feel good to treat people well.
But then one day you noticed that not everyone plays by the same rules. They consistently get more from you than they give in return. They trick you, play on your emotions, and employ all means necessary to unfairly get more for themselves.
Even your own child has gotten good at the bedtime tantrum for securing more storytime. And at work, it is a similar dynamic. You find yourself getting roped into tasks that no one else at your level ever has to do.
How did things get this way?
First, not all people are manipulative or controlling. Plenty of people want to do their part and cultivate good relationships.
But, there is a significant subset of people that have gotten really good at pushing the right buttons to get you to do what they want you to do, even if it's unfair or against your interest.