Most people find happiness in the small things in life.  A new survey conducted by Hilton Doubletree finds that the top-voted mood-booster among respondents is stumbling upon money they forgot they had.  Other top reasons to smile also include sunshine, getting something for free and going to bed at night with freshly washed sheets.   Four out of ten say having something sweet to eat puts them in a good mood.  A third say they are usually happy for 75-percent of their week, and 82-percent believe the happiest moments in life happen when you least expect them.