Is it normal for your parents to disagree with everything you say even when your right?

Except you arent right. 

What makes you think you're right and please don't tell us you're still living at home.

It's probably time to not care if your parents agree with you all the time at this point. You need to live your own life as you see fit.

It might feel like that when you want something your way. They probably want the best for you. 

Dude cognitive decline sets it and it’s not worth it. Your energy is best spend elsewhere