I always get weird looks when I tell people I don't want kids

I'm 18 years old. I feel like a lot of people in this sub are just like "Oh I'm in my 30s and I don't want kids. I've realized it's better to not have kids." But I've known for years I don't want kids. I truly believe kids are too much work and I don't want to deal with all the paperwork and stuff you need to do for a kid. When I tell people I don't want kids I get weird looks, and like "Oh you'll change your mind when you're older!" But I don't think I will. I'm pretty set in my decision.