I did know you were going to say that, yes. [Proud smirk? Proud smirk. But it's just something to bypass the real story and make Chat not suspect a thing even as Baymax appears to be posing still.]

Tadashi started with robotics first and...when I was a kid I wanted to do it, too. So I did. We've been inventing stuff together since I was really little. I didn't even know he was making Baymax until he was done and he brought me to his lab to introduce us. For a while Baymax wasn't entirely into the idea of being a superhero but I think he gets it now.