2 Answers

Problems are making people sad?  Why do people always have problems?  Is that you question?
If so, yeah, people have problems all the time.  Sometimes they are overwhelming and people get depressed about them. 
Sometimes people create their own problems. 
Sometimes people don't understand the world does not revolve around them.  When you add the rest of the world to your existence, you will encounter problems. 
It's like driving your vehicle.  There may be no one else on the road, but you still gotta stop at the signs and lights that tell you to stop.  There are limits to how fast or slow you are supposed to go.  If NO ONE else is around, why can't we just do what we want?  Do you think that would make a person happy all the time?  Or would that cause a whole new set of problems? 

Oh, dang it. Go and have another piece of cake...