The Lord's Prayer and the 23 Psalm

I was thinking this morning about The 23rd Psalm and Lord's Prayer as read in the KJV of Matthew 6:9-13. Specifically, the word "want" draws my attention; "The Lord is my shepherd, I shall not want". What was the writer of the Psalm really trying to convey? Was he expressing that because he looked to the Lord as his shepherd all his wants would be met? We first need to understand the word "want". The online Encarta World English Dictionary gives one definition as "to feel the lack of something". I believe the writer of the Psalm was expressing that when the Lord is his shepherd, he doesn't feel the lack of anything. Then I was thinking about the Lord's prayer. Before He taught them the manner in which his disciples should pray, Jesus said ". . . your Father knoweth what things ye have need of, before ye ask him". Then He taught them how they should ask for those things they really need (according to our Father in Heaven). I believe he taught them that their needs are 1) daily bread, 2) forgiveness, and 3) deliverance from the evil one. When Jesus Christ is my Shepherd, these needs will be met and I will not feel the lack of anything because nothing else will be more important than those needs.