There's an old saying, "You'll catch more files with honey than with vinegar." The sooner you learn this, the easier your life will be. People are more likely to assist you or do what you're asking if you are kind (or sweet... like honey.) This isn't always going to be your first reaction. (After all... you were born into this family so I already know you'll be passionate and strong willed.) Sometimes you're going to have to bite your tongue and approach people and situations from a different angle. Stop and think about the big picture and use your head.
A little bit of kindness can go a long way.