Protip: you can come in to Brussels through Amsterdam. Passport control line in AMS is negligible (at least at 5AM, though I'm sure it's not  too bad at other times either), and it's only a 2h train ride straight from the AMS airport to Brussels.

I’m confused is there a passport control for those flying from within EU?

chain rewards the curious | initial contributor at @interface | /interface /wijuwiju /walkthewalk | online at app.interface.social/wijuwiju.eth

probably meant airport passport control in AMS. Schipol airport is quite efficient, but yeah if you're flying from within Schengen no need to go through control, maybe he was outside Schengen or coming from Asia?