Sheldon (Iain Armitage) in Young Sheldon. (Warner TV).

"I've not lived through any of this," said 12-year-old Iain Armitage of Young Sheldon's setting (the fourth season takes place in 1993). "So I look at some toy and go 'What is this, what is its purpose, why would anyone play with this?' And everyone else will go 'Oh, I used to have one of these' and I'll be like, 'What?'"