Sleep aids in abstract reasoning as well. During sleep, especially slow-wave sleep (deep sleep) and REM sleep, the brain processes and consolidates information from the day. This consolidation helps move short-term memories into long-term storage and reorganize them in more abstract forms, making it easier to identify patterns and connections between ideas.
Discussion
Good point.
I read about abstract reasoning and agency thing in this blog, if you're interested. He pulls from a number of popular sources (mentions them anyway), so might be stuff you've read, but found it thought provoking