Time Boggling
The "butterfly effect" is a time phenomenon that states: If you move something even as little as a blade of grass in the past, you will radically change the present.
Little actions make big differences.
If it is true that stepping on an ant in the past could have stopped WWII, or the possibility of shooting your grandfather before your father was born(we've all heard of that paradox), does that mean that time travel cannot exist? Well yes and no. There are arguments for both sides, and several theories explaining alternate time lines, alternate worlds even, but I shall avoid those. Instead I'd like to focus on the idea of changing things for the future.
If it is the case that you can literally change the world by moving a blade of grass, what are you doing with your little moments? You will effect the world in untold ways for generations to come based on how you decide to spend a Saturday afternoon. I cannot really say what is the best plan of action. I am merely suggesting that you be conscious that what you do today will have an effect on tomorrow. Be aware of your actions and do not let the opportunity to change the world pass you by.