The thing is, there are several sub-clauses:
1. The Bible also tells us that we are to put God's will before our own. Paul prayed three times that the thorn in his flesh would be removed. Jesus Himself prayed three times that His cup would pass or, that God would find another way. The answer in each case, was no. Jesus then says, "Pick up your cross and follow me." For some of us, that cross may be living the rest of our lives alone.
What we pray for may not be God's will or it may not be the right timing.
2. God may indeed be saying yes, but He will also not override free will. I've heard interesting discussions about the fact that many of us may not be married because a) we are not willing to marry the person God chooses for us, and/or b) that person may not be willing to choose us.
3. God always sees the bigger picture... and our prayers may not be answered the way we want simply because as part of His eternal plan, He chooses something else for us.
I'm not meaning to be discouraging, just realistic. When my spouse left, all the good Christians gave me all the "cheery, upbeat" Christian cliches and Scriptures about finding myself in the Lord, enjoying my alone time with God, Christian service, and being so young (I was 25) that I'd find someone "in a year or two" or " stop looking, you'll find someone when I least expected it."
It's been 15 years and I've gone through all the phases and fulfilled all the advice that was ever given to me--several times over. When you can start talking about time passing in DECADES... a lot of time is passing by.
I GREATLY resent the fact that people were not realistic with me and while I want to encourage others, I abhor the idea of telling people the same gut-wrenching things as was told to me. I have watched many other people around me go through divorce, remarriage, not being able to have kids... and they are almost all now married (for several years) and have not just one but multiple children...
I keep trying to tell myself, somewhere amongst all that, even while He's fulfilling the dreams of all my siblings and friends who are 10 years younger... God hasn't forgotten me. Sometimes I need to remind myself of that more than once.
Yes, I've spent LOTS of time in study, prayer, and Scripture but you know why? It's because I'm opposed to people who preach "Empty Optimism" laced as "Christianity" without any sense of reality. Can God do anything? OF COURSE!! But in 99.999 cases, does He choose to swoop in with some mind-bending, instantaneous, LASTING miracle? From my observation... if this is what you're waiting for... Be sure to eat regularly along the way, or you will surely starve. 
