Thiel’s talent was recognized very early: after primary school he got a place at the Oberrealschule Bender in Breslau free of charge after successfully completing an intelligence test. After only three months he was able to jump one year, and until his final exams he was always top of the class.

In 1929 he passed his Abitur exams, he got As in all subjects.

Thiel had a very close relationship with his brother Herbert, who was eight years older than Walter. Herbert, who was a precision engineer and, later, just like his father, worked as a communications technician with the postal services, supported the family financially.