For an instant change I suggest you'd break out of some of your usual habits. Since I don't know what those are, take my suggestions with a grain of salt:

Don't go home after work - join a gym, go bicycling, walk thru the city till it gets dark.

If you're used to go to bed early - stay up late and spend the next day at the office trying not to fall asleep.

If you don't hang out during the weekends - call some of your friends and get really wasted.

etc.

The point is getting new perspectives on life, new experiences will help you find out what you really want and need.