Why is the ninth month called September?
to leave quickly
a vogue word of 1905, "to leave in a hurry," perhaps a variant of skedaddle (q.v.). The association with twenty-three is as old as the word, but the exact connection is obscure.
Then skidoo, little girl, skidoo.
23 is the number for you.
To depart hastily; scram • Often a command or a bit of advice: We heard the shooting and we skiddooed quick/ Skidoo, skidoo, and quit me
[1905+; perhaps fr skedaddle]