Motivation

Are you motivated with what you do in life? be it work, hobby, study, charity, whatever...
I used to be quite motivated at work, will work as hard as I could, and does not need much return (well, I did get good returns (?!), but I really do not expect it when I was putting in my effort), and I guess, like everyone else, passion dies, for whatever reason, maybe the samething for too long, or different environment that I do not like, maybe samething in constant change that irritates me. But yes, like everyone else... my passion dies too
How do you re-motivate yourself?
Sometimes, there are rewarding events, that could motivate you, last time, it works wonder
but the recent ones, despite was even better than the previous ones (depends on how do you see it), the adrenalin rush was just way too short. I got a bit excited about it, and was telling everyone about it, but 2 hours later, the feelings are gone, and I'm no longer feeling motivated and wanted to put in my best at any price.
I wonder, where would my new passion be?