I have found that sometimes you can pray and pray for something and it just never comes. Usually, after some thought, I realize the thing I was praying for was not for the best anyway. I've even noticed that sometimes you are praying for one thing and get some other, often better thing instead! Now, I'm not necessarily talking about material items, like Tahitian pearls, although what a beautiful request that would be :)
I'm talking more about situations and needs vs. wants. My brother is a union carpenter and has been out of work for a while. It seems just when he's on the last plank of reserved means, the Lord provides. Someone called him today with a new work opportunity. Congrats, bro and thank you, Lord! You know what we need even before we ask. I wouldn't put my faith in anyone or anything else!