Out in the meadow

The Lord is my shepherd, I shall not want. (Psalm 23:1 KJV)

Other translation says "I lack nothing (NIV)" instead of "I shall not want". In my understanding, it means "I have my shepherd, and it is enough."

But how could I, as human, to be in a state of not wanting anything? I mean, it should be very fundamentally human to want something. I want to take a shower, I want to have fun, I want to eat good food, or even I want a tablet and I want a Google Glass.

So, what does it really show in that verse? How could one say that God's enough?

Maybe what David meant after all is that God knows all we want and need, like a shepherd knows the favorite place where his sheep could feed, the freshest water where his sheep could drink from, and the warmest valley where his sheep could grass and safe out of dangers. Maybe David knows that he should not worry about a thing, for he's got the Mighty Shepherd watching his back.