For example, unlucky people tell themselves that they didn't win a sweep because they never win. Lucky people are more likely to say that they lost this one, but they'll win the next. Which type of person do you think is more likely to keep entering, and therefore win more?
The same holds true outside of sweepstakes entry. Unlucky people don't take risks because they assume they'll never work out. Lucky people brush themselves off when something doesn't go their way and look for new opportunities.
In order to keep a lucky attitude, remind yourself that good luck always follows bad.