Before Yishion went back to hometown, he had already able to sleep on his own without mummy or daddy tapping on his. This is due to Mummy would hope to train him be independent earlier. This is because last time, he would need us to tap on his back until he sleep. That makes him feel soothe and sleep fast.
After training from mummy, he was able to go to pillow and lie down to sleep on his own.
But now, he seems to forget what mummy teach him again... Really a headache for mummy when no cooperation given by old folks.