I was really angry at work yesterday, due to different reasons. Now, I start to wonder if I’m too selfish.

Should I angry just because my work load is more than other teammates? Maybe, the supervisor thinks I can handle it so he gives me more jobs. Should I angry just because I have to do the late shift when the other person wants to take a day off? It just one hour later than my usual shift, and it’s not like I have a date after work or something. I just stay at home after work no matter what time I finish anyway. So why do I feel angry when they ask me to do the late shift?

Is it because I’m selfish?