Dean's world is dominated by dad and Sam. Sam's proportion was larger, he admitted. So he thought it was natural that even if he occupied such a large part of Sam's world, it would not be very small, right? This idea was not narcissistic.
That's why Dean was so angry after the incident in Paradise.
But in fact, long long ago, the story had a very sad prequel. Do you want to read it?
Conception: