Preparing For A Hike

I never realized how much work actually went into planning an overnight hike.  This is my first overnight hike and I thought it would be a lot like camping...boy was I wrong.  When I go camping first off my car is packed full of everything I can possible think of because you never know if you will need it or not.  But when it comes to hiking, you only have enough room for important items as you are carrying that weight on your back.  Although my hiking bag is pretty big, I can't go overboard otherwise I will not be able to make it up the Mountain.  So how can you decide what items are more important than others?  To help me figure out what's more important, I created a list of everything that I would bring camping and then I would start eliminating items.  Like a pillow, sorry pillows are huge and take up too much space...or how about pots and pans...those are heavy and large so we won't be bringing those either.  It seems like I have to downsize everything and I am okay with that.  As long as I have food, water, and a shelter I am ready for anything!