That habit is believing in myself. Believing in yourself, believing that every goal you set can and will be accomplished is the foundation to success.
Simply put, If you want to accomplish anything in life, YOU have to believe you can. You have to believe in yourself and your ability, because there will be times when no else does. The habit of self belief will be the engine that drives you through the negativity and doubt.
Henry Ford put it like this; "Whether you think you can, or think you can't, you're right."
Why do I call it a habit? Well, you need to do it, practice it, make sure that it gets burned into your mindset. It's like brushing your teeth in the morning, you do it without thinking about it.
Believe in yourself! Set your goals and go after them with everything you got!