Promises, promises, only a word

Why must God promise things to His children and then wait before He fullfils them. Abraham for instance was promised to be the father of many nations and yet God waited till he was far beyond the years of having children and His was was no longer able to bare children. I know God wants to show His great and awesome glory and He has the way that is best but still it feels so unfare to be on the reciving end of such things.
When I am here I do not feel loveingly towards the situation. I do not wish to embrace it and hold on to it. For the Hope that is cast aside so many times becomes painfully dear to my heart. The longing that must be pushed aside seems stronger each day. God is molding and shaping me and it hurts. I have asked that my life be a wittness to His greatness yet still it hurts. It's as though I have willingly said Lord Bend me and break me (well at times I have). But doesn't He know that I don't like it. I want to be great in His eyes but I don't want to work for it. I don't like having to wait for the things He has said He would give. But as a child who waits on his parents for the gift that is to come there is more joy in the recieveing so to speak. So here I will wait with patients from God. He will fill my heart with more of Him and His desires. And each time I lay my dreams before Him, He is seeing them and knowing them and I am coming closer to Him.
Again I lay down my dreams before God and I ask that He be the Lord of my life. He has given me His all what else can I give but mine in return.