Verbalising pointless negative thoughts will make them more real.
The Challenge: Try not to complain about anything for 24 hours.
1. Write yourself a reminder of what you're doing, somewhere that you'll see all the time.
2. Keep score of the number of times you nearly whinge.
3. Don't give up if you accidentally complain about something, either reset the 24 hours or keep a tally of how many slip-ups you make.
4. Fix, or ditch, a problem instead.
5. Try and identify 'useful' complaints and whether or not they're worth failing the challenge for. If someone is stealing your bike = complain. You can't find your sock = don't.
6. Think of things that you are grateful for, instead.