Have a visitors day and when lots of people say how lucky you are to be able to do what you do and you must have the best job going, that should sort you out!
Failing that, just look back at how quickly time has passed since you started flying and make a note of how long you have left. Then have a brew and think about how much you'll miss it when it's all over.
Ultimately and this is the one!!!...
Take out 5 mins and watch Helo Thunder;
http://www.metacafe.com/watch/6150/helo_thunder/
...and remember, when those guys leave, they'll be after your job!!