Some of you may remember this one. The famous line from the movie Forest Gump...
"Life is like a box of chocolates... you never know what you're gonna get".
This was a line repeated time and time again. And in a sense it's very true. You don't know what you're gonna get outta life. You can't decide each and every thing that will happen from day to day. But you can have a big impact on what you get outta life. You can make good, strategic (meaning thoughtful) decisions each day that more than likely will decide what happens tomorrow.
If you just say, I don't know what I will get outta life, so I might as well not put too much effort into it, you are just setting yourself up for failure. Just because you can't guess the whole future, doesn't mean you shouldn't plan. You absolutely should plan, think, make decisions, and drive your own life, never following those who will lead you the wrong way.
So sure, life is like a box of chocolates, and sure you may not know exactly what you're gonna get. But you can decide to buy or not buy those chocolates each day. And you can be smart enough to read the label, so you may know whats inside (think of the consequences of your actions or decisions). Then you will know.... "what you're gonna get."