Lucky people notice what's going on.

Dr. Richard Wiseman

Wiseman surveyed people self-described as "lucky" and "unlucky".   The lucky finished a task in seconds while the unlucky took two minutes at the same task.

"[Wiseman] gave both the "lucky" and the "unlucky" people a newspaper and asked them to look through it and tell him how many photographs were inside. He found that on average the unlucky people took two minutes to count all the photographs, whereas the lucky ones determined the number in a few seconds.
How could the "lucky" people do this? Because they found a message on the second page that read, "Stop counting. There are 43 photographs in this newspaper." So why didn't the unlucky people see it? Because they were so intent on counting all the photographs that they missed the message.
Unlucky people miss chance opportunities because they are too focused on looking for something else. They go to parties intent on finding their perfect partner, and so miss opportunities to make good friends. They look through the newspaper determined to find certain job advertisements and, as a result, miss other types of jobs. Lucky people are more relaxed and open, and therefore see what is there, rather than just what they are looking for."