Your password is needed to log into your account. It is best to use something you remember, but that is not one you use for any of your other games. Such as your Minecraft or Battle.net accounts.
Changing Your Password
Like many account settings, they can be accessed on the My Account page.
Under the "Account" tab is where you can change your password. This password is the one associated with your Curse account.
Simply type in your current password and your new one, and press the "Save" button to change your password.