Task: Determine the prevailing emotional tone of the tweet, categorizing it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that most accurately represent the tweeter's mental state.
Tweet: @Mysteri759 @Ren102e906 @slb42jcb @swoozyqyah Well, I'm too old, and too stubborn about facts &amp; history to be discouraged.
This tweet contains emotions: 
anger, pessimism, sadness