also possible he didn’t learn to write roman letters until he was out of grade school? Not sure what alphabets he would have learned in indonesia.
I do; it is a variation of Arabic (though it apparently lets you drink beer; Indonesians will toss back some brews). Even when it was a colony (Dutch East Indies) until after WWII, they had that Arabic-looking script (like Farsi in Iran or Ordu in Pakistan) on their money even when the Dutch held it...