"Wrinkling your brain" is "adding complications to your previously overly simplistic mental model"

Wrinkling something makes it more nuanced, more complex, more capable of handling subtlety.

Fractally-wrinkled things are more resilient.

You can't wrinkle someone's brain without their permission.

They have to be motivated to accept brain wrinkling in that context from you.

It's much easier to wrinkle someone's brain when they already have momentum in the direction where the new wrinkles would form.