Learning boundaries is important, even if it means being disappointed—not everything is always going to go your way. Sure, when you're one year old, something you were interested in suddenly disappearing might be the worst thing that's ever happened to you, but it's important to learn that lesson now because once you're older, learning that same lesson gets a lot more inappropriate and embarrassing. There's a big difference between a 12-year-old throwing a public tantrum because they didn't get…