The importance of planning cannot be overemphasized.
THE FACT
It helps you to properly manage time and resources wisely.
THE BIG FACT
I have experienced many times when a plan does not work. Like today I planned to attend a meeting but couldn't due to a delaying vehicle that was recently repaired. So you see? A plan does not always work.
THE BIGGER FACT
From what I've learned and experience, I've come to understand that a plan is not complete without a plan B.
PLAN = plan A + plan B