At one point in my high school days, I decided to never share or give answers to my classmates because I was blamed for getting a low score. Yes, that happened to me!
There was this one classmate who would always compare her math homeworks with my answers. We used to top the math exams, in other words, there was a competition going on between the two of us. But we were friends, at least that was how I see it. Until one day she came to me and asked for my answers.
She said she was not confident of her answers so she asked me if she could copy my answers. At first, I did not want to give my answers because it would be my advantage to be on top of the math class, but because she persistently beg for my answers, I eventually gave my answers to her. She was very furious after the checking because she scored very low in the test, and she blamed me for that! She told me that she was wrong about asking answers from me.
Now that I am a teacher, I always want to incorporate cooperative learning and group work which allow the students to share their ideas and thoughts in their respective groups. But, I also strictly implement the no cheating policy during examinations. I tell them to never share their answers to anybody. I would say,
"Any form of communication is not allowed! You are not allowed to talk or to make signals. Consider your answers your girlfriend or boyfriend. Would you like to share your boyfriend or girlfriend to others? This is the time to be selfish because sometimes we need to teach other people to be independent and self-reliant."
And after that, I would be distributing the questionnaires to my students and start the test. And I think that is very effective to do because I see my students focusing only on their own papers and answers. So yeah, maybe I am somehow teaching them to be selfish in their education.
As for me, selfishness is not totally wrong and negative. We should also be selfish about some things in our life in order to teach others to stand on their own, because we can never expect other people to help us at all times. Helping has limitations because some people may abuse the help that we give to them.
These are the things that I am very selfish of:
So, in conclusion, I am teaching my students to be SELFISH sometimes because again not everybody deserves our precious time, our helping hands, and our unlimited energy!
This is participation to the weekend-engagement initiatives of 
All images are mine unless stated.
