I'll throw in my explanation too:
Your first choice is either right or it's wrong. If you switch, right becomes wrong and wrong becomes right.
Your first choice is 1/3 right 2/3 wrong.
Your first choice is either right or it's wrong. If you switch, right becomes wrong and wrong becomes right.
Your first choice is 1/3 right 2/3 wrong.
I think there's a psychological component too. So many probability questions are about random events so you (very naturally) take a position that the revealed door is randomly chosen. It is NOT - you always see one of the goats.
You may be on to something.
Perhaps part of it is not wanting to switch from a winning position to a losing one. Thats harder to take so inertia sets in.
This is reminiscent of the endowment effect: https://en.wikipedia.org/wiki/Endowment_effect
I struggled with this because I didn't see the first choice as relevant to the final outcome. It is easy to see the game as restarted somehow when the 50/50 choice is presented.