没有什么兴趣动力阿
well, we can take it this way: a praise with a smile comes off sincere and makes people motivated; a critisism with a smile might be taken as a kind one, which pushes you forward; a declination with smile is an understanding one, which helps you through hardship;a request with smile is a genial one which helps you crack nuts.
We may understand is: Brings the smile praise, is the person feels sincere, can enable the person to advance boldly; Brings the smile criticism, make the person to feel the good intentions, can press the person to be progressive; Brings the smile rejection, make the person to feel the understanding, can help the person to go out the difficult position; Brings the smile request, makes the one feel kind, can help the person the attack.