Don't get uptight over little things. Flight delays can be really annoying, but stressing about setbacks only makes them worse.
Take the time to chill out in Departures, and why not buy or borrow a Greek phrasebook and learn a few handy essentials or have a massage - departure lounges are fab these days!
Plan to arrive two hours before your flight and check out the airport website to see what you can do with your wait in advance.
You may be able to book beauty treatments or a posh meal to really get you in the mood.
If, instead of blazing sunshine, you end up with pouring rain for 13 days of your holiday, use your imagination.
There are still loads of other things you can do: board games, walks in the rain followed by cakes and treats, funny photoshoots with the family, etc etc.
Turn unfortunate weather into an opportunity for maximum fun and everyone else will too - especially kids, who naturally invent spontaneous fun.