Big O took about 15 minutes to teach. Sure, it went on and on a bit because a rigorous class will introduce proofs, but you are absolutely right - it's a trivia

Big O took about 15 minutes to teach. Sure, it went on and on a bit because a rigorous class will introduce proofs, but you are absolutely right - it's a trivial concept, and often flawed in practice (list is supposed to be faster for random inserts/deletions according to big O, but in practice they are almost always slower).