When you're a child you're able to assimilate so easily into any situation. You even start talking like the people you're around. I wasn't conscious that I was so good at that until I started to truly feel like an actor.
With Altman, he does discuss everything with you, but then leaves you to it and gives you full rein and lets you improvise and create a character while the camera is rolling.
Some scenes you juggle two balls, some scenes you juggle three balls, some scenes you can juggle five balls. The key is always to speak in your own voice. Speak the truth. That's Acting 101. Then you start putting layers on top of that.
