Even though the future is unpredictable, you should still have a vision and set goals towards achieving them.
When you decide to go somewhere, that's a goal. You plan out how you will get there and what route to take. There may be an obstacle or two, but no matter what, you know where you are going.
Now what if you just got in your car and just drove, without having a clue where you were going. You would probably get lost. This us how you should perceive you life. But having a vision of where you want to be heading. Then start making a plan of how are you getting there. Things may be tweaked along the way, but you are okay because you know where you are headed.
Remember that God only has one gear: FORWARD. So don't dwell on past disappointments. We all have them. Because that will only keep you stuck in the past.