I beg to disagree with this. Choose a strong password, do write it down and store it in your safe/bury it in your garden/wherever. You are far more at risk of forgetting a strong password than someone guessing it (and if its a weak password, changing it every Tuesday is not going to help at all). But yes, backup your wallet, everywhere. If the password is strong enough then its safe even if some cracker gets his hands on it. And if you're paranoid use cold storage (paper wallets), and keep multiple copies of them too.