If Ben were still a ghost it's hard to say how long they might have stayed that way, on the floor of a random corridor, clinging to each other and unwilling move. Fortunately or not, Ben isn't a ghost any longer. Once his body has recovered enough from the panic, Ben remembers why he had gotten up to leave the goop festival in the first place. He was hungry. Is hungry.

Depending on how much Cole is paying attention, he may notice the way that it impacts Them, Ben's hunger. They notice it even before Ben, and it agitates Them a great deal. Causes pain - though it may not be immediately clear whether this distress is physical or something closer to emotional, or some equivalent thereof. What is clear is that They respond to it, even when Ben only has a vague inkling of some kind of physical unease.

At this point, who is to say whether Reginald discovered a peculiarity in Ben's powers - that the connection between Them and Ben was stronger and more unstable when Ben was hungry - and exploited that to his advantage while training Ben by denying him food when he deemed it necessary to make him cooperate... or whether there was no peculiarity to start with, and it was that repeated cycle of starving Ben into using his powers, and Ben's misery afterwards, that forged this bad association at all. The chicken and egg situation here is murky. What is clear is that They don't like it, any time Ben feels the beginnings of that sort of hollow ache in his stomach. It makes Them restless and wild and volatile.