Chimps have a much better working memory than humans. They can also count 100 times faster than humans. However, the area of their brain responsible for this faculty is used for language in humans... The theory is that the prior working memory and counting ability may have been optimized out at some point to make physical room, assuming human ancestors could do it too.

Lookup the chimp test. the videos of the best chimp are really quite incredible.

There is also the measured inflation of map traversing parts of the brain in pro tetris players and taxi drivers. I vaguely remember an explanation about atrophy in nearby areas of the brain, potentially to make room.