I'm a second year physics student and since last year I've been noticing that an old habitis becoming a serious problem: when I can't solve some exercise in a set, I literally can't do anything with respect that subject until I solve it. It has became something quite similar to an OCD. I already tried to cultivate that Polya's (I'm not so sure) mindset/habit/strategy which says if you can't solve some problem you can try solve an easier problem and then try to solve the original again. But sometimes occurs that the concepts are reasonably clear, the easier problems are solved and well understood, but some specific problem seems just unsolvable. An extension of that problem is an internet dependence, I mean, I feel very uncomfortably when I study far from some computer because If I can't solve something I usually search for the answer when my ideas of approaches to solve/understand it are exhausted. While I don't find the answer, I just can't proceed. Then a computer became something like a guarantee of study productivity. So I want to know what do you do when a wild problem appears and you can't defeat him at the first moment. Do you just move on and try to work on another one? Which mindset I should have to deal with that craze?