Have you ever heard of a self-fulfilling prophecy? It's where someone, in an attempt to keep something from happening, actually causes the event to happen. For example, if you knew you were to die in an accident tomorrow, you would probably stay home and in bed, right? That way, you couldn't be killed in a car accident. So, you stay home only to discover that it was a home accident and not a car accident that kills you. By trying to avoid the event, you actually brought it to pass.
Do you think maybe that's why God doesn't show us the entire plan for our lives? If He did, would things work out the way they're supposed to? Probably not. We would see the hard times, try to avoid them, and end up causing much more pain in the process. Too much information is not always a good thing.
God knows we have enough to deal with if we simply take one day at a time. Today will have enough joys, enough troubles, enough laughter, and enough tears. It is all we need, and all we can handle. Let's leave our tomorrows in His hands. He has a plan. He knows how it will unfold. We don't need to know what tomorrow holds. We only need to know Who holds tomorrow.
Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof. - Matthew 6:34