Spoiler Alert: I am about to reveal the main point of the entire Harry Potter series, including Movie #5, Order of the Phoenix.
Friendship and Love are the most important things in life.
Trust your friends. Look out for them. Follow your heart. Tune in to your instinct. Have confidence in your own abilities, and also recognize that you can't always do it alone.
I think that's why I like the series so much. Plus the fact that it is a total escape from reality, like a mini-vacation from being stuck inside my own mind.