[glaukopis]

I feel similarly; the author mentions spending ten minutes trying to solve one of these puzzles, and I can’t imagine doing that and enjoying it. Maybe it’s the case that spending more time on the ones that stumped me would yield fruit, but I have the impression that on this class of problem, if I don’t see the solution within two minutes then I probably won’t be able to figure it out in ten, which disincentivizes investing time in them. I’d be interested in knowing if the people who /can/ solve all the problems in the article do so by investing time in them and being methodical or if they just “see it” eventually, which is how I feel solving the easier ones.

There’s also the factor that some Bongard problems, independent of their difficulty factor, are just more satisfying than others. Spoiler for the fourth one, with pairs of circles: its solution is that the entries on the left have $property while the ones on the right...don’t. This makes the right side virtually useless except to check the rule that you derived from the left side.

Maybe it’s just that I don’t have research experience, and am thus unsteeled against problems that seem impenetrable, or maybe I just don’t have the mindset to be good at these, but I agree the really difficult ones can be frustrating.