Task: Evaluate the tweet for emotional cues and classify 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 indicate the tweeter's state of mind.
Tweet: A #smile doesn't always mean a person is #happy . Sometimes it simply means they are #strong enough to face their own #problems .
This tweet contains emotions: 
joy, optimism, sadness