Task: Categorize the tweet's emotional expression, classifying it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that reflect the tweeter's state of mind.
Tweet: It is not joy that makes us #grateful . It is #gratitude that makes us #joyful .\n - David Rast
This tweet contains emotions: 
joy, optimism