All the great miracles in the Bible were done to further the Gospel, not to further personal, materialistic, selfish ambitions. So, as James says, we ask and receive not, because we ask amiss.
That said, when I approach God, I do it with the expectation of a "yes" from a gracious God. I have been in personal crises and emergencies, even life-threatening circumstances where I have cried out, and received help.
I was in a bicycle race not many years ago, and the crank of my bicycle fell off. I carried on walking, thanking God for His grace, knowing that he was going to help me finish the race. I came to a pickup truck where someone just happened to have a bicycle crank in the back, and he fixed my bike and I finished the race. The cherry on top was that I still beat my son to the finish, even after walking for 25 minutes. God just likes to show his kindness and glory to those who expect help from Him. Does not every child expect help from their parents, who are not half as benevolent as God?
I'm not selfish! I do this and I do that and I do other things to. I'm always doing for God and I do in the open to so he can see everything I'm doing.