In church today I heard this story about John Wesley(founder of Methodist church) that when he was about 18 or 19 he met a dock worker. The dock worker was paid very little and didn't even have a mattress to his name. Yet he was one of the happiest people John ever met. John asked the worker how he could live and work in such lousy conditions and still be happy.
"Because I am alive and know God(Jesus Christ) will always be with me. For that I will always be happy and thankful toward God," replied the dock worker.
It was at that point John, while believing in Christ, began to understand what it means to be happy and even thankful.