Hi, I'm not sure if this is the correct sub-forum to post this question, so I apologize in advance if this post is misplaced. Anyways, a little about my self: I'm a Junior in high school, My passion is in physics and mathematics and I plan to major in physics and preferably get a PHD in it in the future. My goal right now is to improve as much at physics and mathematics as I can. Now to my question: I've been noticing lately that I sometimes fixate my self on a difficult physics/mathematics problem and would spend hours at a time trying to solve it (sometimes it can take up my entire day). 99% of the time my attempt is in vain and I feel like I just wasted my time doing a problem when I could of spent it on something like doing my homework or solving problems that I have a higher chance of solving. So I've been wondering if there is any benefit to spending hours doing a problem only to get no solution at all, or would it be more beneficial (learning wise) to just do problems that I can solve confidently? Any advice(even unrelated to my question) will be highly appreciated! Thanks!