To learn or to unlearn. That is the question.

The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn. ~ Alvin Toffler 

According to a English dictionary (google dictionary), unlearn is defined as "discard (something learned, esp. a bad habit or false or outdated information) from one's memory." Or unlearn is defined as "to forget and stop doing (something, such as a habit) in a deliberate way because it is bad or incorrect (Merriam-Webster)". 

My question about learning and unlearning is "When we have to learn and unlearn?" 

And my simple answer is "Whenever we learn, we have to unlearn." Because learning and unlearning is a coin (human cognition, affection, and behavior)'s double sides. 

More thoughts from others. 

10 Life Lessons You Should Unlearn

http://www.huffingtonpost.com/2013/10/14/life-lessons-to-unlearn-martha-beck-advice_n_4058438.html

Importance of unlearning

http://www.hb.org/the-importance-of-unlearning/

Organizational Learning and Unlearning: 

"The study investigates how issues related to organizational unlearning affect each of the four stages of the transfer process, namely initiation, implementation, ramp-up, and integration. Its findings indicate that organizational unlearning is an important source of stickiness in inter-organizational knowledge transfer."  

http://www2.warwick.ac.uk/fac/soc/wbs/conf/olkc/archive/oklc6/papers/tsang.pdf