Why “should” is not effective
While speaking with ourselves and others, we use words, tone, and body language that help to convey what we intend (and often what we do not intend) to communicate. We attach meanings to words. The word smile has a positive connotation while the word manipulation has a negative one. The words that we use can indicate strictness or softness. Psychologists feel that the impact of certain words is immense like the word should. Rather than using should, they say that we are better off using could or would.
Giving up Shyness
Here’s a nice read on sacrificing shyness when one grows up.