I used to think "D" was an optional letter of the alphabet, because once my kindergarten techer once skipped it while singing the alphabet.
A childhood belief about spelling

others believed things like this
- In preschool, I thought that the letter N came twice in the alphabet- W X Y N ZAnon
- i really thought that "key" was a secret letter to the alphabet that only i knew.— amber
- that the twefth letter of the alphabet was "elemeno" like: a b c d e f g h i j k elemeno p— feivel
- I used to believe there were two "N"'s in the alphabet. As in... L, M, N, O, P..... and X, Y, N, Z.— kim
- I used to belive there were two N's in the alphabet, one after M and one before Z.Anon
- When I was little I thought that you said minnow in the alphabet. You know m, n, o...— Brandy