Here's the scene tonight at bedtime:
Me: "Sebastian, I have an idea. Why don't you take your dinosaur and blanket and hop into bed. I'll come and rub your back."
Sebastian: "Okay" [He run/hop/skips over to the bed, dinosaur and blanket in tow and climbs into bed.]
Sebastian: "Momma, I have idea too."
Me: "You do, huh?"
Sebastian: "Yeah. Where's idea?" [he sits up in bed and looks around the room]
Me: [laughing] "You can't see an idea, sweetie. An idea is in your head."
Sebastian: "Momma, get idea out. [grabs hair] I wanna see it."
Me: "An idea is pretend, you can't see it or hear it or smell it."
Sebastian: "Oh, okay. Momma you have idea, I have idea."
Yep.