Having Nightmare

Hi Daddies & Mummies, My son (27 months in PG now) had nightmare recently. On Monday, it was terrible that I had to bring him to the temple & prayed. Thereafter, his nighmare stopped. However, yesterday & today, he cried & refused to enter the CCC once we reached. Instead we loitered around till he was satisfied to enter the CCC (that was yesterday). For today, he didn't even want to enter the CCC & I had to drag him in. Only then his Chinese form teacher managed to pacify & settled him down. May I know what is the main reason? Was he frightened by the new kids onboard or something else? Thank you!