With age comes wisdom and experience. In Qui-Gon's case, said experience keeps his questions in check, despite the fact that there are many. That nonchalant shrug clues him on Ezra's general attitude towards his own birthday: he's can't or doesn't want to make a big deal out of it. Regardless, Qui-Gon wants to respect those wishes.

For the most part.

"I see."

He nods at Ezra's response and gestures to the kitchen.

"Help yourself to some of the cupcakes. I'll be back in a moment. Please excuse me."

Without waiting for a response, Qui-Gon strides back to his room, the bag still in his hands.