Sometimes you're experiencing the fruit of bad karma, sometimes the fruit of good past karma. You have to learn to adjust your attitude to fit in with the rhythm.

"The Thais have an expression for understanding karma, what they call the “rhythm”of things. The teaching on karma doesn’t say that you have a single karma account, that the karma ripening right now is the sum total of all your past karma. Instead, it says that specific actions will bear fruit at specific times. If someone is experiencing bad karma right now that doesn’t mean that all they have is a load of nothing but bad karma. It means that a particular unskillful action is bearing fruit right now. That person may also have other good actions in his or her past that have not yet borne fruit. So you can’t judge the total karmic past of people by their position in life, by their current level of happiness and pain. The teaching on karma is not meant to be used that way. You can’t look at somebody and immediately gauge their karma account.

What is does mean is that there’s a rhythm to life. Sometimes you’re experiencing the fruit of bad karma, sometimes the fruit of good past karma. You have to learn to adjust your attitude to fit in with the rhythm. In other words, if the past karma is such that nothing seems to be working right now, you have to develop patience, develop as positive an attitude as you can. Focus on what areas you can affect, i.e., your intentions right now. Make sure your intentions are good; make sure you intentions are skillful. As for the things that you can’t affect, well, just let them go. Sometimes the rhythm of karma is such that it may take a while. So you learn patience, which is another skillful attitude."

~ Thanissaro Bhikkhu "The Rhythm of Kamma"