Take the fear of a layoff, for example. Optimists will often underestimate their likelihood of being laid off. They may see the warning signs and read the same industry news as everyone else, but they interpret the data in a more positive way. While this will keep their stress level manageable, they may also not be fully prepared if they do lose their jobs. They may not have updated resumes or applied for positions in other divisions. On the other hand, they tend to be upbeat about their prospects for new employment.
One of the characteristics that set humans apart from most other creatures is our ability to see into the future; to travel ahead in time. It’s what helps us plan. We can for instance, make a decision to go grocery shopping even though we just eaten a big meal; we know we’ll be hungry later, and we’re out of eggs, so we shop.