I have been boring for awhile.  It's cheaper.  Unless I have a reason to go out (date, the burning desire to get out, try something new), I stay home.  A poll I gathered gave the ages people said they were most fun or boring

27 was the age of "most fun".  37 "boring".

what made us "fun"? Staying out late on a work night, asking someone out, trying a new sport, changing jobs...