I generally do believe the accounts in the yearbook but the reasoning about why things happens often does not make sense.
I think there is a belief that God is much more "hands on" and controlling things than He actually is.
I always think about Solomon's "time and unforeseen occurance" statement that applies both ways, bad AND good.
It's not just the JW's that have these ideas but many other religions also. How often do we hear that "God saved his life" or when some poor person wins the lottery that God had something to do with it.
When a person gets sick or recovers from a disease, I just don't think God had anything to do with it: He didn't purposefully didn't give them the disease or cure them. It was just their own weaknesses or strengths involved (both mental and physical).
It just gets to be too much when someone is quoted as saying, "Jehovah provided me a pioneer partner, or a place to live, or some money for clothes for the assembly, or whatever .......
I'm not saying that there is never divine intervention in certain situations in life. I believe there is. However, I think those situations are the extreme exceptions and not the rule.
Rub a Dub