Past Bad Experience
It is sometimes hard to forget the events that left unmitigated effects in your brain. Your brain is a very effective organ; it retains memories in your mind. The life we are living, The friends we meet and the people who come in and out of our lives leave some memories, and those memories have effects that depend upon the effectiveness of the thoughts. Most of the time we forget the things, messages, memories that have negligible effects on our lives, however, we retain those bullying, harassme