Yes it also happens to me, you are right. Sometimes i am always eager to wait for the person turn to finish for me to raise my own thought like you have said or to show that i know better than you.

I would also like to contribute on the causes of this.

(1) Ego like you just said, pride people wanting to show that they know more better than you as this case has happen to me also.

(2) Difficultly in admitting that you did not know.
This is also the one of the reason, people never admit that they did not know or rather listen to you.
They prefer for you to finish your owb talking then they raise theirs to show that they know.

So one solution to this is to admit sometimes in conversation that you did not know and try to stay cool, listen and gain what you did not know.

Thank you for sharing this great write up with us