To not let things get to you, and
allow yourself not to be bothered or annoyed by actions or the current situation you may be in or by what other are doing to manipulate you into bitterness. When everything is building up. i.e. The saying
when it rains it pours seems to make sense in describing life at times and acting like a duck is better, because ducks do not run and hide when it rains, they do not try to cover themselves up and avoid it, they do not attack the rain or try fighting it off they simply endure it with pride and dignity like it was not even there in fact they seem to enjoy it while it lasts, and above all do not seem to be bothered by the rain. Hence acting like a duck or to act like a duck is better than retaliating and making the situation worse or make everyone think its better to attack and fight rather than be dignified and
work it out.