Subject selections

I'm having a hard time choosing my subjects for next year :( I have a few in mind that i want to do but i'm scared that i won't like them or that i'll lose interest in it. When people older than me ask what subjects i'm planning to pick and i tell them, they always say "ohh don't do that, it's boring and it's hard" or " it'll scale you down". Every subject is gonna be hard, like duhh! Thinking about this just gives me a headache --"