Analyze the following tweet to determine the level of joy expressed. The levels are: 0: no joy can be inferred, 1: low amount of joy can be inferred, 2: moderate amount of joy can be inferred, 3: high amount of joy can be inferred.
Tweet: wow, i really can't believe four years already went by. four years. jeez. we miss you big guy #4yearswithoutcory #corymonteith #glee