Oz Pinoy has a great, unique perspective on life; Your mind is like a fertile garden, whatever you think is what you plant in it; what you think is what you are and if you don't maintain the garden it will start to grow weeds (negativity) so you must fertilize the positive thoughts with sunshine and water and food (positive friends). He also mentions that the mind will sub conciously eavesdrop on actions and words that you make so thinking positively only goes so far; you also need to act and be positive and then you will start to fertilize your goal.
Remember to think positively!