Why is halloween August's favorite holiday?

From the text:

For me, Halloween is the best holiday in the world. It even beats Christmas. I get to dress up in a costume. I get to wear a mask. I get to go around like every other kid with a mask and nobody thinks I look weird. Nobody takes a second look. Nobody notices me. Nobody knows me.

He does not need to show his face he is "him" he feels "normal"

Because he can dress up as anything and nobody see him