As an actor, you have an accumulated knowledge base. But there’s also something about it that every time you really feel like you’re doing it for the first time you have no idea whether you’re capable of it.

Marling is describing a paradox at the heart of acting (and, by extension, any creative craft): experience builds technique, vocabulary, and a store of lived observations, yet the most truthful work can feel like stepping into the unknown. The “accumulated knowledge base” suggests training and repetition, but she emphasizes that genuine performance requires vulnerability—approaching a scene as if it were new, without relying on rote habits. That freshness carries risk: if you are truly present, you can’t fully predict whether the moment will “work.” The quote frames artistic growth not as eliminating uncertainty, but as learning to tolerate it and to keep beginning again.