You're right - some parents accept separation from their kids. Some don't. IDKY. It seems reasonable and rational to expect our parents to accept our reasonable and rational (to our minds) explanations. It seems to be a proof of our own rightmindedness. We think we need for them to accept and approve that we are rightminded, otherwise we are wrong?

"Taking responsibility" for yourself means accepting responsibility for your decisions. For exampke, the big trip. All you would need your parents for is to accept your body to be shipped home if the worst happens, if thats what you decide.

They are not part of your team. They want you to be part of THEIR team, but the rules chafe too much. But they absolutely refuse to be part of your team.