The next time you're late to something, just explain that it's not your fault . . . you're just an optimist.   Here are five bad habits with a silver lining from Business Insider.

Running late all the time.  If you always think you can cram in more things than you have time for, you're probably an optimist . . . and you're just doing it to a fault.  People who are late a lot tend to be people who expect the best, even when it's not realistic.

Daydreaming.  Studies have shown it can help you be more creative.  One study at Harvard found that zoning out for about 12 minutes while working on a difficult task can help you find a solution when you return to that task.

Using filler words like "um" and "uh."  More and more research is finding that filler words actually help us absorb what someone's saying.  Also, people who are hardworking and highly conscientious tend to use more filler words.

Complaining.  But only if you do it right.  People who complain effectively tend to be happier than people who just vent.  So what does "complaining effectively" mean?  It's when you complain about something that can be fixed.  And you direct your complaint to someone who can do something about it . . . not just your cat.