Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: #Sad I #missed #GDragon #tonight in #Seattle.Might be awhile before he's back, I hope everyone who attended the #concert had a #great #time!
This tweet contains emotions: 
joy, optimism, sadness