Wiktionary
brain-bending
a. mental challenging; difficult to understand.
Usage examples of "brain-bending".
I had worn swim trunks during the brain-bending session, just in case of an emergency like this one, so I took Angelina's hand and we trotted to the private elevator.
I had worn swim trunks during the brain-bending session, just in case of an emergency like this one, so I took Angelina’s hand and we trotted to the private elevator.