I've had this. I remember getting stuck when I was 17 on some ridiculous C string parsing problem. I'd been at it for hours when I gave up, went to bed, dreamed about it, woke up and wrote the solution in under a minute.
It was kind of a surreal experience given the amount of effort I had put in the evening before.
It was kind of a surreal experience given the amount of effort I had put in the evening before.