I don’t think it’s an accident that “aha” and “haha” are both almost spelled the same way. Indeed, there is a deep relationship between the Eureka moment and humor — which is one of the reasons why Isaac Asimov once said “The most exciting phrase in science is not ‘Eureka’, but ‘That’s funny!'” And why? Because when something strikes you as funny it is often an indication that your assumptions are being challenged, as in what you were expecting to see was nothing more than a false conclusion cobbled together by the habitual ways in which you interpret the “data.”