The Gifts of Darkness - Chapter 14 - Page 17

There was a much earlier mention about Adrien's previous job as a waiter. He's mentioned some other things here and there, and now you can piece together the full timeline: Adrien dropped out of university without even completing his first year, went to work as a waiter, and lost his job when the restaurant had to close, which is what led to his decision to get into a magical apprenticeship program.