I think you are trying to say that he made at least 2x what you were making. I would be very surprised to find an intern making more than half of what the person they are interning under makes and normally I'd expect it to be much less.
Typically you aren't working at an internship because you have a proven track record of skills in a certain area. That is kind of the point of doing an internship. And having a proven track record is something employers are willing to pay a lot more money for.
You don't have to justify it, I understand all the bullet points. I'm just corroborating the parent's statement that willful ignorance of someone else's wages can be a useful coping mechanism. Because no matter how many justifications there are, it still stung.
Typically you aren't working at an internship because you have a proven track record of skills in a certain area. That is kind of the point of doing an internship. And having a proven track record is something employers are willing to pay a lot more money for.