This is something every parent should hear, and everyone who's had a parent.
You do not owe your parents obedience, or respect, or gratitude. If they deserve these things, you will want to give it to them naturally because when you look at them, you feel these things for them. Respect and gratitude are not mandatory, they have to be earned. Even by parents.
Children are not slaves to their parents. They do not have to obey. And any parent who seeks to control their growing children (past the age where such things are reasonable, for example telling a toddler it is bedtime or a pre-teen not to drink) and tell them who to be, is being a bad parent. As a child is becoming an adult, they become their own person, on their own path, and a good parent will seek to love and support them in finding and expressing who they are.