Antonyms for the phrase "didst impression of" can be a bit tricky to identify, as it is not exactly a commonly used or well-defined phrase. However, if we focus on breaking down the component parts, we can come up with some possibilities. "Didst" is an archaic form of "did," suggesting an action taken in the past. "Impression," in this context, likely refers to a mimicry or imitation of someone or something. So, potential antonyms for "didst impression of" could be things like ignoring, forgetting, avoiding, or refraining from mimicking or imitating someone or something.