There are limits to how much sound a cello can make. That's part of the framing of acoustical instruments. Finding what those limits might be, and then trying to suggest perhaps even the illusion of going beyond is part of that kind of effort.
Yo-Yo MaChildren, in a way, are constant learners. Certainly sponge-like. Absorbing everything without careful analysis, even though, at the same time, they are certainly capable of incredible insights.
Yo-Yo Ma