Let me guess: They're saying that this is for your own good, or some stupid stock phrase like that, right?
No, they really just don't care about my well-being. I'm pretty used to it. The primary decision maker in this process doesn't want to go either, but is going to anyway. Totally illogical. I'm far, far more mature than all of them combined and would probably be better off finishing my developmental process on my own.
Meh, I've been through worse.
Sorry, but this is simply not true. Nearly every single one of us has felt that at some point, and only the tiniest, most unlucky, portion of us have actually been right. You're a teenager, this happens, they're right. I was pissed off at my parents for always 'interfering' in my life, but at the age I was, they had every right to. Hell, they still do, they're my parents.
They do know better.
Uncertainty isn't the problem, I'm absolutely certain as to what's going to happen. I'm going to be subjected to extreme heat, humidity, direct sunlight... and sand.
... Go wading, dig a hole, build a sandcastle, kick over your sandcastle, run away from jellyfish. Write a list of all the things that make the beach so very beachy. Put seaweed on a dog. Collect shells. Get a ridiculous sunhat and enjoy having an excuse to wear it.
Look out at the ocean and understand how small you are.
That's what I do at the beach, anyway. I'm sure you'll be able to think of something to do.
...
I don't understand human behavior.
And that is why they say you need help. Not having a rough understanding of human behavior is a fairly big issue when you're a human being.