Something is simple or complex depending on the way we choose to describe it. Complex problems do not require complex solutions, they require simpler thinking.
I think Edward de Bono said that, but if he didn’t it’s the sort of thing he would have said. Mind you, I’ll bet at least one person per year has said something pretty similar for the last … ooh… 15,000 years?
You’d think we’d have learnt by now, wouldn’t you?