The Mind Of A Monkey
There is a term, "monkey mind", that goes back 1000s of years. Basically your mind is always going - 24 hours a day, 7 days a week. Most of the time we walk around in a zombie-like state and don't even realize that our mind is churning away, thinking crazy thoughts, running through crazy scenarios, bouncing from branch to branch like a rabid monkey.
The initial goal of meditating (to me) is simply to become aware of all this activity, to observe it in action like you are an un-attached third party. Once you do learn to observe it, you will never be the same.