Sometimes when I pray I get frustrated when the "righteous desires of my heart" seem to go unheeded.....this quote from Elder Neal A Maxwell of the Quorum of the Twelve Apostles of the Church of Jesus Christ of Latter-day Saints gives me some understanding I need...........
(New Era, April, 1978)

"Petitioning in prayer has taught me, again and again, that the vault of heaven with all its blessings is to be opened only by a combination lock.  One tumbler falls when there is faith in Christ, a second when there is personal righteousness; the third and final tumbler falls only when what is sought is, in God's judgment--not ours--right for us.  Sometimes we pound on the vault door for something we want very much and wonder why the door does not open.  We would be very spoiled children if that vault door opened any more easily than it does.  I can tell, looking back, that God truly loves me by inventorying the petitions He has refused to grant me.  Our rejected petitions tell us much about ourselves but also much about our flawless Father. By inventorying our insights, from time to time, it will surprise us what the Lord has done in teaching us.  What we have learned in the past can help us to persist in the present.  By tallying the truths and keeping such before us, we can also avoid lapsed literacy in spiritual things.  If we will let Him, the Holy Ghost will bring all the important insights to our remembrance."