Caveat emptor.
I learned this one the hard way.
Last time I prayed to God to teach me patience, God answered within days. Answer? I was made to wait for the next 10 YEARS...! Very painful lesson.
But I asked for it myself. God simply gave me what I asked for. I was being taught patience. Thankfully, I was intelligent enough not to pray for strenght also, or I would have calamities added to the wait, to build up my strength as well. Then I understood what it meant:
"And lead us not into temptation, but deliver us from evil"
Pray for deliverance and receive deliverance. Pray for difficulty, and receive difficulty.