War
Over a thousand gazes were fixed on Nero, which is why the pressure he felt was not just psychological. Aether was dancing in the air, responding to the surging emotions, almost as if it was just as infected by the sage's words as everyone else.
Unfortunately for Nero, that meant that when the sage, and everyone else, looked at him, the aether responded and crashed down on him. If he had not learned to increase his internal aetheric pressure, and gain momentary strength, then just the weight of the aether would have been enough to cause him to stumble.
But it was not as if Nero was completely spared. It was clear to anyone looking that Nero seemed to be struggling, and that he was doing everything in his power to maintain a stoic expression on his face. Without understanding the actual immense pressure bearing down on him, they could only imagine Nero as a young child suffering flashbacks of a traumatising night.