If you feel like doing something, what's stopping you? Don't let it be your negative attitude.
Be the first one with the "you can do it!" type of encouragement when you get an inkling of what your goal is that day/week/month/year.
If you don't like your current situation find a way to change it.
If the way you've been carrying your life hasn't given you any results you feel proud of, then you know there is time to make some changes. Get out your comfort zone - that change will expand your horizons, give you a different perspective where you might gain new knowledge on how to go about changing what's not working in your life/job/career/relationship.
Don't be afraid of failure.
Be afraid of never trying.