even when you sleep, your mind is still working, with meditation, you're trying to clear your mind of all thoughts in an attempt to let it 'sleep'. since life is really busy, we need time to relax and unwind and meditation brings that. studies have shown people who meditate are more alert, focused, and calm. while we meditate, we open our 'mind' and we begin to see things clearly, since our subconscious catches more than we often catch on, we see visions of events, or answers to tough problems. we also listen to our bodies while we meditate, so you might be able to pick up on little things. as we meditate, and turn our brain off, going deeper into meditation, our spirit begins to take over, and we can connect with the universe.
here's a link: http://www.ineedmotivation.com/blog/2008/05/100-benefits-of-meditation/ the site lists 100 reasons why meditation is beneficial to a person. hope this helps ^_^