I sympathize because I tend to be a slow thinker as well in some ways, but really, how fast one can solve a problem is a feature of how intelligent one is, and

I sympathize because I tend to be a slow thinker as well in some ways, but really, how fast one can solve a problem is a feature of how intelligent one is, and bad sleep or illness does decrease one’s ability to think intelligently (and not just in terms of speed).