Most kids' misbehavior has a cause you can understand. The prefrontal cortex doesn't mature until age 5 to 7, and young children can't focus on multiple things at once. Learning how your kid's brain actually works makes you less reactive.
Chapters
One of the very best things you can do to become less reactive, including taking things personally and yelling at your child, is to educate yourself on child behavior and development as much as you practically can. There is almost always a reason for your children's behavior that makes total sense. It's usually something happening inside of them or around them that's not their fault. And most difficult behavior is because your child simply doesn't know what to do with those things when they're happening. For example, before a child is five to seven years old, they don't have a functioning prefrontal cortex, which means, among other things, that they can't attach to more than one person or thing at once. This can mean that sometimes they're going to look like they're ignoring you, and other times they're going to get very locked in on things.