There's something you might have missed. When I approach a problem like this I notice I solve it only after I give up. It's not spending 15 minutes to go over

There's something you might have missed. When I approach a problem like this I notice I solve it only after I give up. It's not spending 15 minutes to go over all assumptions that makes me solve it. It's telling someone I can't solve it. It's the act of saying I can't do it. I often start writing an email telling someone I can't solve a problem, and while writing I realize something I haven't tried. Then I stop, go try it, and it turns out to solve the problem. But if I don't start writing that email, and instead try to work on the problem for 15 more minutes, I don't solve it. It's as if I don't take the problem seriously otherwise. This is very similar to the 15 minute rule, only it's more efficient, since it takes less than 15 minutes to write that email. So I would argue solving the problem has more to do with admitting you can't solve it than it has with going over assumptions. It triggers something in your brain that frees it to look at options it hasn't looked at before. I thought it was the possibility you might embarrass yourself to the person you are emailing that helps solve it. But the strange thing is I also solve problems only after I send that email. My mind refuses to look at the problem from a different angle otherwise.