Why are nparents literal toddlers?

Do you ever realize how much nparents are really just like toddlers? Like my nparents every time I talk to them I realize how little comprehension they have whenever I speak to them and even if I broke it down for them they still don't understand what I'm talking about. It's even worse if I try to get them to repeat what I said and they can do that but somehow come up to different conclusions. Not to mention the absolute lack of control of their temper. Both my nparents quite literally cannot talk without getting mad. They get mad over such menial subjects. Everything has to be THEIR way. THEIR perspective. Anything else and it is wrong. Literally it's just so weird. Obviously I hang up every time they have their little tantrums, but still these are grown ass adults. How the hell did they make it up to this point and have kids. It's such a weird phenomenon to see. Now that I'm a little older and emotionally mature I'm able to hold my composure and just see that none of this shit is worth getting mad over. I still hate that it is possible to go through nearly 60 years of your life and never had the thought "Am I the problem?"