Is the human brain really the most powerful computer in the world? | Notes and queries

The long-running series in which readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific conceptsI keep seeing references to the human brain being “the most powerful computer in the world” (as well as sometimes “the most complex thing in the universe” – how would we know?). But is the human brain really more complex, or more powerful than that of the other primates or great whales etc? The human brain di