Groot's awareness of the past is not gone.

It is dormant. As he grows, and as he is prompted, his memories wake. He thinks of things he has not thought of in some time, and they mean things they did not mean then.

The languages of most people he has met are strange and difficult. It took a long time to learn how to listen to them. Repetition helped. One thing he quickly grew accustomed to hearing: What is that?

And –

But –

The significance, at the time, was mostly lost between the cracks of his comprehension where most nuance used to fall, registered as an anomaly without connotations, but now the memory comes back and it is brand new and means everything: a new person, smaller than most he has met, looks him up and down, turns to the others but then back to him, opens his mouth and –

And who're you?