The bizarreness effect refers to the human tendency to easily remember information that is strange, unusual, or "bizarre" more so than it is to remember mundane facts and figures. This is caused by the human interest in information that is novel, strange, or unusual and the tendency for memories to fade more for mundane information.
For instance, many children (and adults) are able to learn and remember a lot of information about dinosaurs while having difficulty remembering much about academic information that they consider boring. Another example would be recalling different days of your daily commute.
For example, you would be much more likely to recall the specific day that you saw a fender bender involving clown cars on the side of the road (something very unusual or bizarre) rather than the days where nothing unusual or bizarre happened.