This month I will focus on the following:
Mentally strong people avoid wasting energy on things they can't control.
Mentally strong people don't complain (much) about bad traffic, lost luggage, or especially about other people, as they recognize that all of these factors are generally beyond their control. In a bad situation, they recognize that the one thing they can always control is their own response and attitude, and they use these attributes well.
(This is #4 on a list of 13 things mentally strong people avoid which was compiled by Amy Morin, a psychotherapist and licensed clinical social worker).
The first three points on the list are in my blog archives, posted on the first of the month in February, March and April.