Think of it this way: planning for negative scenarios is generally implies that you're willing to deal with them. To be willing to deal with them, you probably think that you're capable of dealing with them.
Even though dealing with negative situations isn't kittens-and-puppies happy, it is solidly optimistic. That's the kind of positive thinking that helps you.
Even though dealing with negative situations isn't kittens-and-puppies happy, it is solidly optimistic. That's the kind of positive thinking that helps you.