Why no birthday present for me?

Went to fetch the kids from school today & Nickson told me : "teacher didn't wish me happy birthday & the class didn't sing birthday song for me, other people's birthday have but my birthday don't have". Didn't know this would meant so much to him & I told him not to get angry over this as the teacher might have forgotten as there are so many students in the class & we have celebrated his birthday yesterday & he got his birthday present too. But I believed these are not as good as his teacher remembering his birthday & his classmates sang him a birthday song.