Hard to think of a movie that aged more poorly than "Bowling for Columbine"
Once you know that the reason Klebold and Harris shot up their school was that they were neo-nazis targeting minorities and girls, the whole movie and Michael Moore's sympathy for them play out very differently.
Of particular note is the scene where serial sexual abuser Marilyn Manson highroads the audience and Moore talking about how he'd have prevented Columbine by sitting down with those kids and listening to them.